The high rate of population increase in Nigeria arouses the question of birth control and one of the ways of achieving such is through family planning. This paper examines the positions of religious adherents on family planning in Nigeria using Effurun and Kano as samples. The broad objectives of the study include the exploration of the knowledge of family planning among religious adherents; finding the differences in the position of religious adherents with regards to family planning; finding the association between the knowledge of family planning and their socio-demographic characteristics; and investigating the association between the socio-demographic characteristics of the respondent and their position on family planning. The study used the survey method in which data was collected through a structured questionnaire which was distributed among 450 religious adherents spread across Christianity, Islam, and African Indigenous Religion in Effurun and Kano metropolises. Out of this, 334 were retrieved from respondents. The result shows that 71.6% of religious adherents support family planning as an effective means of birth control irrespective of their religious affiliations and beliefs.  This suggests that religion may likely not be an inhibiting factor to the success of any policy of birth control in Nigeria. This paper contributes to knowledge on the aspects of religion and population problem in Nigeria and as such recommends strong legislation on birth control.