Taxis are the safest means of transportation in Rio de Janeiro (other than the subway), and there are over 32,000 taxis in the city. The vast majority of drivers are polite and honest, driving regulated cabs.
Because the supply of cabs is so plentiful, you will not have any difficulty finding one even late at night in Rio (except on rainy Friday and Saturday nights). Depending on distance, most one-way rides will cost R$12-27; US$6-13.50; €5-12 in a yellow cab (except to the airport, which is more expensive than that range).
The most common type of taxi in Rio de Janeiro is the Táxi Amarelo (Independent Yellow Taxi)
Reliability is very good, despite a small minority of drivers who may take a longer route than required, propose a flat rate [sometimes in their favor], or return incorrect change to you. You should be fine by taking these ones for short distance rides in the city perimeter.
Fare is metered: R$4.70; US$2.35; €2 (flag-down), plus R$1.70; US$0.85; €0.70 per km (R$1; US$0.50; €0.40 per mi). There are two tariff scales for any Rio de Janeiro yellow taxi, determined by several factors: weekday/weekend, time of day, holidays, Carnival, etc. As in most countries, taxi meters calculate the fare based on both distance and time elapsed, without reference to the number of passengers. Fares are never “per person.”
Note: whenever there is a fare increase, taxi meters are not immediately updated, and drivers determine the correct fare in accord with a table affixed to a side window.
You hail a cab by flagging it down as you would in any large city. These taxis are yellow, with a blue stripe along the sides. Some taxis display the word livre (free), or ocupado (busy).
For further relevant information on taxis (including taxi to/from the international airport) and other means of transportation in Rio de Janeiro, download an updated edition of My Rio Travel Guide – The Essential How-To Visitor’s Guide to Rio de Janeiro (the e-book in PDF format that will make a whole lot of difference during your visit to Rio!).