We tested the effectiveness of the American Biophysics Corporation Mosquito Magnet® Pro Model (ABC-PRO) to reduce mosquito abundance in an urban (Wolseley) and in a rural (Fort Whyte) setting in Winnipeg, Manitoba in 2001 and 2002. Assessment was based on comparisons with control sites by using Centers for Disease Control (CDC) light traps and landing counts on human observers. Over a period of 94 trap nights, the ABC-PRO collected more than an estimated 2,000,000 mosquitoes of 6 species. Aedes vexans dominated trap catches in both years. Ochlerotatus sticticus was the 2nd most abundant species at the rural site in 2001, and Coquillettidia perturbans was the 2nd most abundant species in the urban site in 2002. When consideration was made for the confounding effects of wind speed and temperature, there were no significant differences in landing counts at Fort Whyte in either year, although CDC trap catches were significantly greater in the ABC-PRO location in 2001. In Wolseley, there were no significant differences in CDC trap catches in either year, although landing counts at the ABC-PRO site were significantly higher in 2002. We could not demonstrate that continuous operation of the ABC-PRO in these 2 locations in Winnipeg significantly reduced mosquito activity.