Purpose The purpose of this study was to evaluate the screen time used by Autism Spectrum Disorder (ASD) children and its association with their physical activity and weight status. Design/methodology/approach This cross-sectional study was conducted among 100 purposive sampled children registered under the National Autism Society of Malaysia centres in Kuala Lumpur. Parents-administered questionnaire composed of socio-demographic, anthropometric data (height and weight of the children), Autism Severity Questionnaire, Screen Time Questionnaire and Physical Activity Questionnaire for Older Children (PAQ-C) was used in this study. Findings Respondents in this study were categorised as having mild ASD (55%). Most of the respondents had higher screen time (78%), with average (4.14 ± 3.19) h spent using the devices. The respondents had low physical activity level (54%), with average PAQ-C scores of (2.38 ± 0.79). Average BMI-for-age z-scores was 1.06 ± 2.15, which was in the normal category. Approximately, 34% of the respondents were overweight and obese. BMI-for-age was positively associated with screen time during weekdays (χ2 = 11.06; p < 0.05) but not during weekend (χ2 = 3.14; p > 0.05). Spearman correlation test showed negative relationships between screen time on weekdays (rs = −0.30 and p < 0.01) and weekend (rs = −0.21 and p < 0.05) with PAQ-C of this group of ASD children. Practical implications Screen time was directly associated with the BMI-for-age z-score but was inversely associated with physical activity. Future studies could implement a structured physical activity intervention among children with ASD, which may increase physical activity and decrease screen time behaviours while addressing the overweight/obesity and cognitive aspects of these ASD children. Originality/value This study measured the amount of screen time, level of physical activity and weight status but not dietary intake of autistic children.