In rabies endemic regions, a proportionally higher incidence of rabies is often reported in dogs younger than 12 months of age, which includes puppies less than 3 months of age; this presents a serious risk to public health. The higher incidence of rabies in young dogs may be the effect of low vaccination coverage in this age class, partly as a result of the perception that immature immune systems and maternal antibodies inhibit seroconversion to rabies vaccine in puppies less than three months of age. Therefore, to test this perception, the authors report the virus neutralising antibody titres from 27 dogs that were vaccinated with high quality, inactivated rabies vaccine aged three months of age and under as part of larger serological studies undertaken in Gauteng Province, South Africa, and the Serengeti District, Tanzania. All of these dogs seroconverted to a single dose of vaccine with no adverse reactions reported and with postvaccinal peak titres ranging from 2.0 IU/ml to 90.5 IU/ml. In light of these results, and the risk of human beings contracting rabies from close contact with puppies, the authors recommend that all dogs in rabies endemic regions, including those less than three months of age, are vaccinated with high quality, inactivated vaccine.