A comparative investigation was carried out on criteria for the reproductive performance (n = 590) of 114 imported and 86 locally born Friesian cows reared under semi-arid conditions in Saudi Arabia in 2 farms. No significant differences were found between the two groups as regards the resting time, first service to conception interval, service interval, conception rate, and insemination index. The conception rate was low (46%), and the insemination index-services per conception-was high (2.16). The season had no significant effect on the reproductive performance. Significant differences were found in the conception rate and insemination index of both groups between farms, with lower results for artificial insemination. Heat stress and adaption problems are seen as causing the low conception rate and insemination index. Measures for improving the reproductive performance of Friesian cows in Saudi Arabia are outlined.