They are aggressive and they speak English! Just walk away. Do not engage them. If you speak another language, start speaking it. They tend to hang around the major tourist areas (i.e. Pc do Comercio).
A tale from fellow travelers on a business trip, who told the beggar to "bugger-off" in so many word. The beggar actually followed them to a restaurant. He continued to harass them from outside the restaurant. The owners did not intervene. The couple were frightened to leave. So I repeat, do not engage them.
Other tales of theft. Camera's left on the table, bags stolen etc. Just be wary. My advice, keep your wits about you and you'll be fine, just like in any city.
There are people in central Lisbon that will approach you trying to sell sunglasses and when they get your attention (and even if they don't) they offer drugs.
It is not unusual also to be approached by older women (over 50) trying to sell drugs.
They are usually gypsies (they usually dress in black, even on very warm days).
This happened to me on a daily basis when I was working in Lisbon, so it is not only an issue for tourists.
I have seen "transactions" happen in broad daylight...
The Rua Augusta and Rua das Portas de S. Antão (behind the Theater) are the streets where you are most likely to be approached.
However, if you say no, they usually will not insist.
Well, Lisbon at night is beautiful. Strolling at night you can admire illuminated monuments, amazing views from the belvederes to the river, the bridges and to the charming streets.
But never walk alone at night because Lisbon can be dangerous like all big towns.
More properly called Roma, are abundant in Lisboa and can be a nuisance to travellers. Whether outside restaurants or hanging around outside the metro station, groups playing songs on accordions and tambourines often approach tourists in search of a charitable donation. The Gypsies are often overly persistent in this persuit, and getting away from them can be a hassle. Gypsies will sometimes approach you and grab your hand without warning to give you a "palm reading," at the end of which they will demand payments as high as 10 Euro. Refusal to pay leads to further harassment.
If you are in Lisbon get used to the fact that there are a lot of people begging for money. They will try to ask friendly, then it can get more rude. They also send their children, you feel sorry and give them some money... suddenly all cousins, brothers, sisters and friends come up to you for money. They will show their diseases like once one showed me his skin (he had skin cancer) while i was having a drink and a bite on a terrace. When you want to park your car they will jump on your parking spot (or they were allready standing there) and pretend they are helping you to park your car and at the end you have to give money (if u dont they will scratch your car when you are gone) etc etc. The best tip is to be rude and consequent and just say NO and walk on, ignore them and thats it. If you feel sorry you will spend a fortune on them and they still will be rude. Sometimes it can be very confronting, while you are on holidays siting in the subway going from place A to B to see something there are blind people in the subway the whole day walking up and down the tube asking for money.... It's sad but it's reality.
Be aware that you're likely to encounter some beggars in the metro, train and outside some stations. Also, I've noticed some beggars in the Rossio square - so if you sit at a table outside a cafe, they'll probably approach you. If anybody approaches you at night or in a deserted area, think twice before picking your wallet.
Lisbon is still one of Europe's safest capitals, but as in any other capital city, be aware of petty crime. Pickpocketing is rather common in the most popular trams such as the 28. However, with common sense you should have a trouble-free visit.
A common harmless annoyance downtown (especially in Rua Augusta, Rossio, and Comercio Square) is being constantly approached by Gypsy or Moroccan immigrants trying to sell you sunglasses and then drugs. They can be annoying, but they are harmless. They go away when you show no interest and say no.
I can't tell you how many times we were offered drugs in Lisbon. More than any other city in Europe that we visited. I didn't think we looked like the type that does drugs, but maybe it was just because we are American. We also had people trying to sell us sunglasses, and they wouldn't leave us alone. Just try your best to avoid these people selling things on the streets because they are a real annoyance.
While walking around Lisbon, I was amazed how often people approached me to try and sell me drugs. They seemed to come in waves, as I got rid of one another was approaching. I have heard from other travellers similar experiences.
Avoid to stay stoped at the corners of Teatro D. Maria building, in Rossio. You will noticed large concentrations of ethnical groups from africa, and as soon as they spot you they will come to sell drugs. Some tourists robbed time to time, or undercover police could come and you're in a trouble. However you should not avoid Rossio it's a safe place during daytime, just don't stay on this corners for long time. Because this is a high tourist concentration area, expect to have a lot of beggers bugging you for money. Stay alert.
As a tourist you are an easy target for drug dealers who will offer you stuff on the street.
Many people will try and sell you goods, some of it is so obviously stolen,just say no,(preferably in Portuguese!)
Often you'll see women with children. Sometimes the children are drugged to make them sleep while the women ask for money.
As in all big cities,be aware of who's around you ,of pickpockets and enjoy this beautiful city. Despite this caution, I still feel this is a very safe city compared to London.
You should avoid this area of the city. It's located in the middle of Avenida Almirante Reis nad it's a really dirty zone in all aspects that you could imagine - drug dealers, prostitution, ethnic confrontation. Also is, in my opinion, one of the ugliest places in the city. Don't waste your time going there.