Some progress has been achieved in reducing the prevalence of undernutrition among children under 5 years of age in Tanzania. In the Rukwa region (2010), the level of stunted and underweight children was 50·4 and 13·5 %, respectively. The aim of this study was to assess the nutritional status of children under 5 years of age, feeding practices and risk factors of undernutrition in a rural village in the Rukwa region, as well as to discuss the results in light of a similar study conducted in 1987/1988. This cross-sectional study was conducted in 152 households with children under 5 years of age. Data were obtained from the child’s main caretaker and the household head, using a structured questionnaire and a 24 h dietary recall. Children’s length/height and weight were measured. The prevalence of stunting and underweight was found to be 63·8 and 33·6 % (Z-score<−2 of WHO 2006 CGS), respectively. Sugar-water was given to 72·3 % of the children on the first day after birth. A thin gruel was introduced after a median of 2 months (25th–75th percentiles; 1–3). The time mothers spent farming was a significant risk factor for stunting (P=0·04). Illness, food shortage and dry-season cultivation were significant risk factors for underweight (P<0·01). Using the NCHS/WHO 1983 growth reference (<75 % of the median), the prevalence of underweight was 25·0 %, similar to that reported in 1987/1988 (26·4 %). In conclusion, the underweight prevalence was found to be at the same level in 2010 as was recorded in 1987/1988. Current child-feeding practices were not in line with WHO recommendations. Women working in farms, food shortage, dry-season cultivation and diseases partly explain the children’s poor nutritional status.