Purpose: This study was aimed to assess knowledge regarding RLS among medical teachers and medical students. Method: ‘Knowledge about RLS (K-RLS)’ questionnaire was developed, validated and used to assess knowledge of study participants about RLS. It was applied to 50 medical teachers likely to get patients with RLS in addition to 324 undergraduate medical students. Results: Individual item validation ranged between 0.8 and 1. Average scale CVI (S-CVI/Ave) was 0.95 for the whole questionnaire and universal agreement (S-CVI/UA) scores for whole of the questionnaire was 0.75. K-RLS had good internal consistency (Cronbach’s alpha = 0.89). Results showed that knowledge regarding RLS was poor among students as well as medical teachers. Conclusion: K-RLS is a reliable tool to assess knowledge about RLS among health care professionals. Knowledge about RLS is poor among medical students as well as teachers.