Objectives: The aim of this study was to investigate the incidence of white spot lesions (WSLs) and its relationship with various patient and treatment variables, in patients treated with self-ligation and conventional ligation orthodontic bracket systems. Methods: Two-hundred randomly selected patient records (136 female, 64 male) for self-ligation and (108 female, 92 male) for conventional ligation groups were examined to determine WSL development. In the self-ligation group, Damon 3MX (Ormco, Glendora, Calif) brackets had been used, and in the conventional ligation group, Equilibrium 2 (Dentaurum, Phorzeim, Germany) had been used. Labial surfaces of 24 teeth in the pre- and post-treatment photographic records were scored using the WSL index. Results: The prevalence of patients who developed at least 1 WSL before treatment was 19 %, whereas after treatment, it was 49 % in the self-ligation and 54 % in the conventional ligation groups. Before treatment, the patients had only mild WSL, but after treatment, severe WSL and cavitation were observed in both groups. Bracket type, age, and hygiene care were significantly associated with new WSL development (P = 0.008, P = 0.004, P = 0.013, respectively). Conclusion: Bracket type and more importantly, the hygiene care therapy provided appeared to influence the development of new WSLs. Ligation can promote plaque accumulation and thereby new WSL development in conventional bracket systems. Clinical relevance: This article investigates the incidence of WSLs in patients treated with self-ligation and conventional ligation. The present study showed that incidence of WSL less in the self-ligation than in the conventional ligation but hygiene care was mostly important factor in developed WSL.