Abstract Background Improving healthy behaviour from childhood could be beneficial both children and families and communities. The aim of the study was to develop the Healthy Lifestyle Behaviours Scale (HLBS) to determine the healthy lifestyle behaviours of primary school students. Methods This methodological study carried out in 521 primary school 4th grade students in two eco-schools in the 2019-2020 academic year. By using literature 120 questions was collected including nutrition, physical activity, hygiene, sleep, environmental cleaning, health responsibility and addiction sub-dimensions. After taking expert opinions, a scale that consists of 54 questions and scored as I agree:3, undecided:2, I disagree:1 and was created named HLBS. In order to evaluate the reliability of the scale, item total score correlation and internal consistency (Cronbach's alpha) analyzes and exploratory and confirmatory factor analysis were used for construct validity. Results Of the 52.8% students were male and their age ranges from 8-11, the mean was 9.5±0.5. After the scale development study, the scale consisted of 53 items and 7 sub-dimensions. The Cronbach's alpha coefficient of nutrition, physical activity, hygiene, sleep, environmental cleaning, health responsibility and addiction sub-dimensions were 0.87, 0.68, 0.85, 0.52, 0.76, 0.85 and 0.76, respectively. The variances of sub-dimensions in the scale ranged from 30.17% to 67.87%. The fit of scale and the fit index were found to be acceptable after confirmatory factor analysis. In the last form of the scale, the score that can be taken from scale range 53-159. It was accepted that by increasing of the score, healthy lifetsyles behaviours were increased. The mean score of the students was 141.39±16.21 and the median was 145.0. Conclusions HLBS was found to be a valid-reliable tool for assesing healthy lifestyle behaviours in primary school students. Key messages Health promotion is an issue that needs to be addressed from school age for developing healthy lifestyle behaviours. In the literature, HLBS seems the first scale about healthy lifestyle behaviours for children and needs to be tested in large groups of children.