This study utilized data on currently married fecund non-pregnant women aged 15-49 years from the 1998 Kenya Demographic and Health Survey (KDHS) to examine the role of socio-economic, cultural and family planning programme factors in explaining regional differences in contraceptive use. The results show that these differences are mainly attributed to the differences in family planning programme factors. Socio-economic conditions play a relatively minor role. Inclusion of an interaction term involving region and knowledge on family planning improve the explanatory power of the model. The main conclusion of this study is that regional differentials in contraceptive use is mainly explained by the differences in family planning programme factors and their interactive effects with the regional level of family planning knowledge