Three hundred and sixty-four records on dairy production obtained from 540 lactations of 145 cows that calved between 1974 and 1994 at the Bambui Centre of Agricultural Research for Development in the western highlands of Cameroon were analyzed for effects of genotype and environment on milk production and reproduction traits. Cow genotypes were Holstein-Friesian (H), Jersey (J), Holstein-Red Fulani F1 (H1RF1), Holstein-Gudali F1 (H1G1), Jersey-White Fulani F1 (J1WF1) and Jersey-White Fulani backcrosses (J3WF1, J7WF1). Effects of genotype, season and year of calving, parity and age at first calving (AFC) were analyzed. The lactation milk yield (MYLD), lactation length (LL), annualized milk yield (AMP), calving interval (CI) and dry period (DP) were also analyzed. F1 crosses (H1G1, J1WF1, H1RF1) and backcrosses (J3WF1, J7WF1) were compared. H1G1 were superior to H1RF1, J1WF1, and J3WF1 with regard to MYLD, AMP, LL, CI, and DP. For AFC, H1G1 were superior to J1WF1, J3WF1, J7WF1, but inferior to H1RF1. Jersey backcrosses were superior to Jersey F1. Milk production of F1 crosses varied from 2.6 times (J1WF1 vs WF) to 4.3 times (H1RF1 vs RF) the yield of local breeds. Among F1 crosses, H1G1 were the best.