Background Child undernutrition remains high in South Asian and sub-Saharan African countries. Rapid declines in nutritional status occur before the age of 2 years, particularly during the period of complementary feeding. Improving complementary feeding practices is a neglected area in nutrition programs. Objective To understand community perspectives on complementary feeding practices in order to inform the design of future interventions for improved complementary feeding. Methods From May through August 2009, data were collected in two rural locations and one urban location in Bangladesh through semistructured interviews, food attributes exercises, 24-hour dietary recalls, opportunistic observations, and trials of improved practices (TIPs). Key informant interviews and focus group discussions were also carried out among family members and community opinion leaders. Results Lay perceptions about complementary feeding differ substantially from international complementary feeding recommendations. A large proportion of children do not consume sufficient amounts of complementary foods to meet their energy and micronutrient needs. There was a gap in knowledge about appropriate complementary foods in terms of quality and quantity and strategies to convert family foods to make them suitable for children. Complementary feeding advice from family members, peers, and health workers, the importance given to feeding young children, and time spent by caregivers in feeding influenced the timing, frequency, types of food given, and ways in which complementary feeding occurred. Conclusions Perceptions and practices related to complementary feeding need to be effectively addressed to improve the levels of child undernutrition. Lack of understanding of children's nutritional needs and insufficient time for feeding children are key barriers to complementary feeding.