Villavicencio, the capital city of the Department of Meta, Colombia, is at high risk for the urbanization of malaria because of the region's ecological conditions, as well as the permanent presence of infected human populations arriving from rural areas. From August to November 2002 and in April 2003, anopheline collections were undertaken in the area. Isofamilies were obtained from 331 wild females, which were then recorded according to their abundance as follows: Anopheles marajoara, Anopheles rangeli, Anopheles braziliensis, Anopheles darlingi, and Anopheles apicimacula. Anopoheles darlingi showed the highest biting activity (3.0) between 1800 and 1900 h. Forty-five breeding places were sampled, 64% of which were fish ponds, 6.7% flooded meadows, and 6.7% drainpipes, with these being the most representative locations. All sampled breeding sites were positive for anophelines. Anopheles marajoara could play an important role as an auxiliary vector in Villavicencio's urban area. Control measures should be aimed at weeding the marginal areas around fish ponds and at evaluating the use of impregnated bed-nets.