Study on reproductive performance of 18 AI bulls and on the efficiency of AI operations wasrnconducted at the National Artificial Insemination Center and in ten purposively selected areasrnof five regional states. This study was also conducted to assess the problems and constraintsrnassociated with artificial insemination service in Ethiopia. The 18 bulls were owned by NAICrnand were in semen production. Questionnaire survey was also carried out on technical staffsrnthat were performing their duties at the National AI Center. Evaluation of number of servicesrnper conception and conception rates to first insemination was carried out. Pregnancy diagnosisrnwas performed on 375 cows in the selected areas. Besides, 114 straws of semen, 61 fromrnregions, and the other 53 from NAIC were checked for semen motility to see if there were anyrndifferences in motility due to handling between the center and the regions. Thirty AIrntechnicians and 246 farmers were used for the collection of data using questionnaire surveys.rnMoreover, fifty-two high-level professionals who have stakes directly or indirectly in thernartificial insemination service have been used for the focus group discussions in the fivernregions. Mean (Â± E) scrotal circumference for Holstein, Jersey and crosses of Holstein withrnindigenous breeds at NAIC was 39.71Â± 0.64, 41.00 Â± 1.16 and 39.00 Â±1.00 respectively. Thernresults did not differ (p>0.05) among the three breeds. Similarly, the outcome of semenrnphysio-morphological analysis revealed that there was no difference (P>0.05) for the differentrnsemen characteristics except for the total morphological defects which differed significantlyrn(P