A comparative study was conducted on joint and nuclear family regarding social, cognitive and language development among preschool children of Ahmedabad, Gujarat. The main objectives of the study were to compare the social, cognitive and language development of pre-schooler children among joint and nuclear family and to identify the association between The URIE Bronfenbrenner’s Ecological Theory of Human Development (1979) was used as the conceptual frame work. A quantitative approach with descriptive study design was used to achieve the objectives of the study. The samples consisted of 300 children from Joint and nuclear family of Ahmedabad. The simple random sampling technique was use to collect the sample. Structured questionnaire was used to assess the social, cognitive and language development among preschool children. The tool was validated by the experts. Cronbach alpha was used to establish the reliability of tools. The tool was found to be valid and reliable. Data gathered was analysed and interpreted using both descriptive and inferential statistics. The study shows that 150 samples were taken from joint and 150 samples were taken from nuclear family. Males were 142 and females were in 158. Man Whitney test shows that there is significant relationship with (joint family) social, cognitive and language development and (nuclear family) social, cognitive and language development. The study reveals that there is significant association between Family income and social, cognitive and language development of pre-schooler while rest of demographic variables are statistically independent with social, cognitive and language development of joint and nuclear family.