Background: Measurement instruments to understand self-determined motivation towards physical activity among college students with intellectual disabilities are needed to develop programs to support physical and psychological health and well-being. The purpose of the current study was to validate a modified questionnaire measuring basic psychological needs towards physical activity among college students with intellectual disabilities. Methods: A total of 108 college students with intellectual disabilities completed the modified questionnaire. Validity and reliability of the questionnaire was examined. Results: Confirmatory factor analysis demonstrated a six-factor model had good model fit. Cronbach's alpha values showed acceptable reliability evidence of the instrument as a whole, although some alpha values in subdomains of the instrument were below acceptable values. Conclusion: The modified questionnaire was found to have acceptable validity evidence. Further studies are needed with refinement of answer options and the addition of more questions to increase reliability.