Athens is generally a very safe city. The streets teem with people and traffic around the clock. Like every big city, there are pickpockets and petty criminals—be especially vigilant with your belongings on public transport. Common sense precautions include:
Avoid leaving your phone lying around on café tables, or it might be snatched.
You might see open drug use in some areas (especially around Omonia and Exarchia Squares, Keramikos-Metaxourgio, Pedion tou Areos park, and Athens Law School). Ignore them and they will generally ignore you.
Avoid Exarchia and Syntagma Squares on days when strikes and demonstrations are planned, as police occasionally use tear gas to dispel protestors.
Police Hotline: 100
Tourist Police: 171 (English, French and German)
Airport Police: +30 210 353 6919
Medical Assistance: 112
Hospitals & Pharmacies: 14944
Roadside Assistance (ELPA): 10400
Fire Brigade: 199