Introduction: Colorectal cancer (CRC) is one of the leading cancers in Malaysia where new cases are increasing every year. The aim of this study was to test the reliability and validity of a newly developed questionnaire on knowledge, attitude and dietary practices (KAP) related to CRC for the Malay population. Methods: The respondents were conveniently selected among visitors attending an outpatient clinic in a tertiary hospital. We excluded those with any cancers, chronic diseases and those that were illiterate. The exploratory factor and reliability analyses were conducted. Results: A total of 108 respondents were recruited of which 67.7% were males and the mean age was 54.59 years (standard deviation 8.93). The Kaiser-Meyer-Olkin (KMO) measure of sampling adequacy values for KAP were 0.64, 0.66 and 0.67, respectively (P < 0.001). The 17 items of knowledge formed five domains with loading factors ranging from 0.54–0.89. The six items of attitude formed two domains with loading factors ranging from 0.64–0.80 and the 15 practices had four domains with loading factors ranging from 0.52–0.83. The total variances explained for each KAP were 61.02%, 56.41% and 53.12%, respectively. The internal consistency Cronbach alpha values on KAP were 0.61, 0.60 and 0.70, respectively. Conclusion: The final questionnaire is suitable for measuring KAP related to CRC among the Malay population.