Obstructive Sleep Apnea (OSA) is a temporary airflow obstruction during periods of sleep. Patients with OSA often suffer from poor work performance, compromised sleep quality, and low quality of life which may lead to a life-threatening event. Adequate knowledge and a positive attitude toward OSA among medical and dental practitioners are crucial to the initial diagnosis and treatment. This study aimed to identify the differences in knowledge and attitude toward OSA between medical and dental practitioners working in North-Eastern Peninsular Malaysia. A comparative cross-sectional study was performed from February 2020 to February 2021. A total of fifty-two medical practitioners and fifty-two dental practitioners working at university-based outpatient clinics, government health clinics, and oral health clinics located in Kelantan State of Malaysia participated in the study, and data were collected by the structured questionnaire including sociodemographic inquiry and OSAKA questionnaire by non-probability stratified random sampling. The Mann-Whitney U test was used to compare knowledge and attitude scores between the two groups. The mean age of the respondents was 34.6 years. The current study shows that 92.3% of medical doctors and 96.1% of dental doctors were able to correctly answer the question "Most of the patients with OSA snore" a significant finding in our study. Only 1% of medical professionals could answer seventeen questions correctly with a median score of 11, and only 1% of dental professionals could answer sixteen questions correctly with a median score of 9. None of them could provide an accurate answer to all the knowledge questions. Medical and dental practitioners exhibited different knowledge levels on OSA (z- statistics=-4.39, U = 827.00 with p < 0.05, and effect size, r = 0.61). However, no significant differences were found in total knowledge score by gender (p-value>0.05), ethnicity (p-value>0.05), total service years (p-value>0.05), and training attended. In addition, significant differences in attitude levels between medical and dental practitioners have been observed (z-statistics=-3.42, U = 725.00 with p < 0.05, and effect size, r = 0.47). Nevertheless, no significant differences have been seen in total attitude score by ethnicity (p-value > 0.05), total service years (p-value > 0.05), attending training on OSA (p-value > 0.05), and professional status (p-value > 0.05) except gender (p-value < 0.05). A Significant difference is evident concerning knowledge and attitude toward OSA diagnosis and management between medical and dental practitioners working in North-Eastern Peninsular Malaysia. Medical practitioners in this study recorded a higher knowledge and attitude score compared to dental practitioners.