Pakistan bears a substantial burden of hereditary and congenital anomalies, with their incidence nearly doubling in the context of parental consanguinity. Consanguineous unions (CUs) are deeply embedded in the socio-cultural fabric of Pakistani society, where longstanding traditions continue to favor such marital practices. This study aims to investigate the determinants and temporal shifts in CU patterns across Pakistan. In this cross-sectional study, data were collected from 5,000 ever-married individuals residing in five major metropolitan cities of Pakistan. Information on marital types, bio- demographic variables, and paternal consanguinity was gathered and analyzed using descriptive statistics and multivariable logistic regression models. The overall prevalence of CUs was found to be 50%, with the inbreeding coefficient (F) estimated at 0.027. Multiple bio-demographic variables emerged as significant predictors of consanguinity. Notably, the prevalence of CUs showed a marked decline among younger age groups, reflecting a generational shift away from traditional consanguineous practices. The analysis further revealed positive trends: rising literacy rates, increased average age at marriage, and a reduction in exchange marriages over time. These socio-demographic improvements appear to correlate with the observed decline in CU rates. This study, based on a robust and sizeable primary dataset, provides compelling evidence of a gradual but significant decline in consanguineous marriages in northwestern Pakistan. With continued social progress, it is projected that the prevalence of inherited and congenital disorders will also decline, driven in part by the decreasing inbreeding coefficient in the population.