Background This study aimed to determine menstrual characteristics and related morbidities among adolescent girls living in Sabah, North Borneo, a less-developed state in Malaysia. Methods Data were obtained from a quantitative survey conducted in three government high schools located in Ranau, Sabah. The participants were adolescent girls who had attained menarche between the ages of 14 and 19. Results Based on the analysis of questionnaires completed by 757 adolescent girls, the mean age at the time of the survey was 17 ± 1.4 years, and the mean menarche age was 12.2 ± 1.1 years. Our data demonstrated that 85.7% of the participants experienced dysmenorrhoea, of which at least 42.1% (mean pain score ± SD: 4.81 ± 0.76, 95% confidence interval (CI) 4.72, 4.90) experienced moderate dysmenorrhoea, and 11.2% (mean pain score ± SD: 7.86 ± 0.94, 95% CI 7.64, 8.08) experienced severe dysmenorrhoea. Over 70% of these girls complained of tiredness, headache, and appetite changes during menses. Conclusions The prevalence of menstrual disorders and related morbidities was high among the girls residing in Sabah. Reproductive health issues in rural and socioeconomically deprived areas remains poorly addressed. The main consequence of neglecting menstrual disorders and their related morbidities is impaired future sexual reproductive health in adults. Thus, addressing adolescent reproductive health issues is crucial, especially for girls living in areas where access to healthcare is difficult. The information gathered from this study can be used to strategize effective interventions to improve adolescents' reproductive health status in rural areas.