Among various elements of population composition, sex composition holds an important place for demographers. The sex composition, in numerical sense, is expressed in terms of sex ratio which is the ratio between males and females in a population. For the analysis of various demographic characteristics and for the planning purpose it is pertinent to collect data for males and females separately. In the discipline of population geography the study of both sexes separately assumes more importance due to their various complimentary and contrasting roles in the socio-economic development of a particular region. This paper attempts to discuss the spatial variation in sex composition in Azamgarh at sub-district (tehsil) level and temporal variation in the district for the period of 1901-2011.