Abstract Background Undernutrition remains highly prevalent in African children, highlighting the need for accurately assessing dietary intake. In order to do so, the assessment method must be validated in the target population. A triple pass 24 h dietary recall with volumetric portion size estimation has been described but not previously validated in African children. This study aimed to establish the relative validity of 24-h dietary recalls of daily food consumption in healthy African children living in Mbale and Soroti, eastern Uganda compared to simultaneous weighed food records. Methods Quantitative assessment of daily food consumption by weighed food records followed by two independent assessments using triple pass 24-h dietary recall on the following day. In conjunction with household measures and standard food sizes, volumes of liquid, dry rice, or play dough were used to aid portion size estimation. Inter-assessor agreement, and agreement with weighed food records was conducted primarily by Bland-Altman analysis and secondly by intraclass correlation coefficients and quartile cross-classification. Results Nineteen healthy children aged 6 months to 12 years were included in the study. Bland-Altman analysis showed 24-h recall only marginally under-estimated energy (mean difference of 149 kJ or 2.8 %; limits of agreement −1618 to 1321 kJ), protein (2.9 g or 9.4 %; −12.6 to 6.7 g), and iron (0.43 mg or 8.3 %; −3.1 to 2.3 mg). Quartile cross-classification was correct in 79 % of cases for energy intake, and 89 % for both protein and iron. The intraclass correlation coefficient between the separate dietary recalls for energy was 0.801 (95 % CI, 0.429–0.933), indicating acceptable inter-observer agreement. Conclusions Dietary assessment using 24-h dietary recall with volumetric portion size estimation resulted in similar and acceptable estimates of dietary intake compared with weighed food records and thus is considered a valid method for daily dietary intake assessment of children in communities with similar diets. The method will be utilised in a sub-study of a large randomised controlled trial addressing treatment in severe childhood anaemia. Trial registration This study was approved by the Mbale Research Ethics committee (Reference: 2013–050). Transfusion and Treatment of severe Anaemia in African Children: a randomized controlled Trial (TRACT) registration: ISRCTN84086586 .