Reporting the Physical Activity Questionnaire for school children's (PAQ-C) test-retest reliability and internal consistency.This was a descriptive study of 100 school-aged children aged 9 to 11 years old attending a school in Cartagena, Colombia. The sample was randomly selected. The PAQ-C was given twice, one week apart, after the informed consent forms had been signing by the children's parents and school officials. Cronbach's alpha coefficient of reliability was used for assessing internal consistency and an intra-class correlation coefficient for test-retest reliability SPSS (version 17.0) was used for statistical analysis.The questionnaire scored 0.73 internal consistencies during the first measurement and 0.78 on the second; intra-class correlation coefficient was 0.60. There were differences between boys and girls regarding both measurements.The PAQ-C had acceptable internal consistency and test-retest reliability, thereby making it useful for measuring children's self-reported physical activity and a valuable tool for population studies in Colombia.