In Afghanistan, malnutrition in children less than 60 months of age remains high despite nutritional services being offered in health facilities since 2003. Afghanistan's Ministry of Public Health solicited extensive community consultation to develop pictorial community-based growth monitoring and promotion (cGMP) tools to help illiterate community health workers (CHWs) provide nutritional assessment and counselling. The planned evaluation in the five districts where cGMP was implemented demonstrated that a mean weight-for-age (WFA) Z-score of 414 participant children was 0.3 Z-scores higher than that of matched non-participants who lived outside of cGMP programme catchment areas. The mean change in WFA Z-scores at evaluation was 0.3 (95% CI 0.3, 0.4) Z-scores higher than at entry into the programme. The most influential factor on WFA Z-score changes in participants was initial WFA Z-score. Those with an initial WFA Z-score of less than -2 experienced a mean increase of 0.33 (95% CI 0.29, 0.38) WFA Z-scores per session attended, while those with a baseline WFA Z-score of greater than zero showed a decrease of 0.19 (95% CI 0.22, 0.15) WFA Z-scores per session attended. These results are encouraging since they demonstrate that the cGMP programme in Afghanistan for illiterate women has some potential to contribute to improving nutrition, specifically in underweight children of either sex who enter the programme at less than nine months of age and attend 50% or more sessions.