Data on 642 Holstein Friesian× Sahiwal cows, maintained at the Military Dairy Farm, Secunderabad, over a period of 19 years (1988-2006) were analyzed. The least squares means of total lactation milk yield (TLMY), 300-days lactation milk yield (300-Days LMY), lactation length (LL), peak yield (PY), milk yield per day of lactation (MYL) and milk yield per day of calving interval (MYCI) were 2864.32 kg, 2593.84 kg, 329.03 days, 13.30 kg, 8.69 kg and 6.40 kg, respectively. Genetic grades, period of calving and parity significantly affected all the production traits studied. Season of calving affected (P< 0.01) all production traits except the lactation length. Heritability estimates were 0.20, 0.18, 0.06, 0.16, 0.27 and 0.17, respectively. The estimates of repeatability and correlations among the traits studied varied from 0.12 to 0.56 and 0.01 to 0.93, respectively.