Human rabies is common in Nigeria, a country known for rabies endemicity. Yet the supply of anti-rabies vaccines for human use (adult sheep brain origin, produced locally, and duck embryo and human diploid cell vaccines, imported) is grossly inadequate. This study involved controlled treatment of dog-bite victims with suckling mouse brain (SMBV) or fetal bovine kidney (FBKV) rabies vaccines in an effort to determine which type to recommend for production and use in Nigeria. Dog-bite victims treated were aged three to 74 years, with about equal numbers of males and females. Of the 136 patients, 116 (85.3%) completed at least the primo-series of vaccinations, and all have survived without any evidence of clinical rabies. Recipients of the SMBV showed local and generalized reactions in 11.1% and 2.5% of the cases, respectively. Recipients of the FBKV administered subcutaneously showed local and generalized reactions, in 12.5% and 9.4% of cases, respectively. There were no side effects attributable to the vaccine among patients who received the FBKV intramuscularly. By day 7, 26.7% of SMBV recipients and 28.6% of FBKV recipients showed antibody response, with titres of at least one Equivalent Unit ml-1. These percentages increased to 95.1 and 81.1, respectively, by day 14, and by day 20 (for SMBV recipients) or day 30 (FBKV recipients) the response was 100%. Titres dropped by day 90, but in no case to below 1 EU ml-1. We have concluded that both vaccines are equally efficacious and well tolerated. In view of the simple technology required, and the resultant lower cost, the SMBV is being recommended for production and use in Nigeria.