•This was the first study to focus on the risk for malnutrition in a general population (family practice non-attenders, living at home).•One in 10 community-living family practice non-attenders had an increased risk for malnutrition.•A screening program at the primary health level can aid in performing early identification of patients at risk for malnutrition. The aim of this study was to determine the prevalence of malnutrition and the factors associated with malnutrition in a population of family practice non-attenders. This would enable us to recognize the extent of the problem and anticipate the measures needed to improve the current situation. This was a cross-sectional observational study in a family medicine setting. Participants were adults living in the community (≥18 y of age) who had not visited their chosen family physician in the previous 5 y (non-attenders) and who were able to participate in the study. Through the electronic system, we identified 2025 non-attenders. Data were collected by community nurses in the participants’ homes. The main outcome measure was the Malnutrition Universal Screening Tool. The sample consisted of 1641 participants (81% response rate). Increased risk for malnutrition was determined in 216 participants (13.2%; 95% confidence interval, 11.6–14.9). The multivariate model showed a significant association of increased risk for malnutrition with age and body mass index interaction (P = 0.022); number of chronic diseases (P = 0.001); poor assessment of current health (P = 0.001); a feelings of loneliness (P <0.001); and increased pain intensity (P = 0.003). A screening program at the primary health care level could help identify patients at risk for malnutrition early. This could be followed by appropriate nutrition support, which may help to reverse or halt the malnutrition trajectory and the negative outcomes associated with poor nutritional status.