A crucial component of safe motherhood is postnatal care. Postnatal care is important for mothers for treatment of complications arising from delivery, especially for births that occur at home. The study utilizes Bangladesh Demographic and Health Survey (BDHS), 2004 data to identify the more important factors affecting postnatal care of mothers in the urban and rural areas. Descriptive and multivariate logistic regression methods were employed in analyzing data. Findings reveal that there exist strong urban-rural differentials in receiving postnatal care (PNC) from medically trained providers among urban and rural mothers. We found that urban illiterate mothers receive two times more postnatal care from medically trained providers than rural illiterate mothers. But receiving PNC from medically trained providers among highly educated mothers is almost same both in the urban and rural area. Receiving PNC from medically trained providers increases with improving the economic condition of mothers both in the urban and rural area. Urban mothers receive more PNC (77 per cent) from medically trained providers as against their rural counterparts (58.6 per cent) who can tell about their pregnancy complications. Regarding knowledge of potentially life-threatening conditions during or after delivery is found very low among the rural women. Finally in the logistic regression analysis we have found receiving ANC and delivery assistance from medically trained providers, type of toilet facilities and told about pregnancy complications have net significant effect on receiving PNC from medically trained providers.