Background: Poor semen quality of pedigree bulls has major economic implications in cattle breeding. Aims: To evaluate the effect of homeopathy on the semen of bulls with reproductive disorders. Methods: The behavioral, clinical and spermatic characteristics of four Nelore bulls were evaluated. The bulls received individualized homeopathic treatment mixed into the feed and administered once per day. Semen was collected using an artificial vagina. Successful collection, freezing, effective doses, and the number of doses of semen per collection were compared before and after homeopathic treatment. Results: The bulls were treated with Sulphur, Phosphorus, Lycopodium and Argentum nitricum all in 30CH dilution. The rates of successful collection were 97.14%, 100%, 96.67% and 30.77% pretreatment and 95.45%, 100%, 94.67% and 96.77% at post-treatment for bulls A, B, C and D, respectively. The average number of doses per ejaculate pre and post-treatment were 102.67 (SD 74.41) vs. 300.08 (SD 180.58), 0 vs. 234.78 (SD 96.12), 0 vs. 105.12 (SD 54.98), 0 ± vs. 107.37 (SD 52.12) respectively. Many of these differences were statistically significant. Conclusion: The use of homeopathy apparently improved the production of viable doses of semen from bulls with previous freezing problems and poor semen quality. Controlled studies should be conducted.