Proso millet (Panicum miliaceum L.) is an uncommon crop in Canada and it is mostly grown in Canadian prairies and in Ontario. This crop is used in birdseed industries and some producers are interested in growing proso millet for this market due to the increasing demand within the last few years. From 2002 to 2005, three types of proso millet (gold, red and white) and five levels of nitrogen fertilization (0, 20, 40, 60 and 80 kg of N ha^-1) were evaluated to determine 1) the productivity of P. miliaceum, grown under a cool and humid climate, and 2) the optimum level of nitrogen fertilization. Treatments were laid out in a factorial design with 4 replicates. During the four years, gold and red proso millet produced more grains and reach maturity earlier than white proso millet. In 2002 and 2005, nitrogen fertilization had no effect on grain yields. However, in 2003 and 2004, grain yield increased linearly with nitrogen fertilization rate. Grains yields increased by 285 kg ha^-1 and 415 kg ha^-1 in 2003 and 2004 respectively when 80 kg of N ha^-1 was applied compared to 0 kg of N ha^-1. These results indicate that gold and red proso millet are well adapted to a cool and humid climate and that a high nitrogen fertilization rate should be considered.