Background: Diabetes mellitus (DM) has become one of the most significant non communicable and rampant diseases. The patients’ level of knowledge is the key element in the self-management of diabetes. Objective: The aim of this study was to assess the reliability and validity of newly translated Malay version of Diabetes Knowledge Questionnaire (M-DKQ) among type 2 diabetic patients. Method: This cross-sectional study was conducted in two steps. Firstly, twenty four items DKQ were adapted from Star County Diabetes Education Study. Secondly, the adapted questionnaire was translated into Malay language. The translation process included; forward translation, backward translation, harmonization, cognitive debriefing and proof reading. The reliability process was done by administering the questionnaire in 50 adult diabetes patients. Internal consistency by Cronbach’s α was assessed. The Content validation was done by a two practicing endocrinologist, two senior pharmacists and one expert in question validation to measure the content validity index for individuals (I-CVI). While content validity index for scale (S-CVI) is measure by two approaches such as universal agreement (UA) and average (AVE). Regarding the face validation done by administering the instrument in 10 adult diabetic patients.  Results: The response rate of this study was 83.3% (50/60). Among which majority were male (56%), Malay (48%) with an age range of 27-35 (28%). Good internal consistency was observed for M-DKQ (Cronbach’s α = 0.71). The study revealed as I-CVI of 0.95. While S-CVI/AVE of 0.97 and CVI/UA of 0.87. Conclusion: The Malay version of diabetes knowledge questionnaire proved to be valid and reliable tool to assess level of knowledge among Malaysian diabetic adult patients. So this study suggests to validate this questionnaire in other populations for further reinforcement.