Breastfeeding practices are critical for child health and growth. This paper investigates demographic factors, socioeconomic status, and information sources that affect breastfeeding practices in Sindh Province, Pakistan. A secondary analysis was performed of data on 10,028 women with a birth in the preceding two years who had participated in the 2013–14 Maternal and Child Health Program Indicator Survey. Multiple logistic regressions were used to test the association between breastfeeding status (ever breastfed and still breastfeeding) and age, number of living children, residence, education, wealth, information sources about breastfeeding, assistance during delivery, and place of delivery. Of the 9955 women included in the analysis, 97.9% had breastfed and 83.9% were still breastfeeding at the time of the survey. Being in the second, third, or fourth wealth quintiles and receiving breastfeeding information from relatives and friends were associated with ever breastfeeding. Women who were 35 years or older, living in a town/small city, higher maternal education, middle wealth quintile, and receiving breastfeeding information from the media were associated with still breastfeeding. The findings suggest the need to develop interventions considering maternal socioeconomic status and peer counseling interventions. Mass media campaigns to promote breastfeeding practices should be accompanied by governmental restrictions on the marketing of infant formula.