Background and Objectives: To evaluate the effect of culturally-relevant food supplementation and psychoso- cial stimulation on infant growth and development. Methods and Study Design: A community-based random- ized controlled trial was conducted in 40 clusters from 5 selected villages in Tanah Datar District of West Su- matera, Indonesia. We assessed 355 infants aged 6 to 9 months at the beginning of the study. The infants were di- vided into 4 groups: 1) Food Supplementation (FS); 2) Psychosocial Stimulation (PS); 3) Food Supplementation and Psychosocial Stimulation (FS+PS); and 4) Control Group (CG). The formula food supplement was comprised of a variety of local food sources (local MP-ASI) and adjusted for the local habits. The quality of psychosocial stimulation was assessed with the Infant HOME inventory method. Progress at 6 months was assessed by anthro- pometry and the Bayley scores of cognition, language and motor function. Results: There were improvements in linear growth, cognitive and motor development of children in the FS (p<0.05) and the FS+PS (p<0.01) groups compared to the CG. After six months of intervention, mean length increased to 6.862.08 cm and 6.662.41 cm for FS and FS+PS respectively (p<0.05). With the combination of food supplementation and psychosocial stimu- lation (FS+PS), cognitive development increased to 21.412.2 points (effect size 0.56) (p<0.01) and motor devel- opment increased to 20.718.4 points (effect size 0.50) (p<0.001). Conclusion: Combined intervention with local food supplementation and psychosocial stimulation improved infant growth, cognitive and motor development.