Objective: Self-concealment is the predisposition to hide negative personal information. The present research examined whether self-concealment was associated with acute and chronic pain. Methods: In Study 1, undergraduate students (N = 44) completed an online questionnaire packet and then completed a cold-pressor task in the laboratory. In Study 2, individuals with chronic pain (N = 85) completed an online survey. Results: Study 1: Trait self-concealment was negatively associated with pain tolerance. Study 2: Self-concealment of chronic pain (hiding aspects of one's chronic pain condition from others) was associated with higher levels of self-reported pain and lower psychological well-being, independent of disclosure of feelings regarding pain. Furthermore, this association was mediated by autonomy and competence needs. Conclusions: Self-concealment was found to be associated with higher levels of pain in both healthy and chronic pain samples. Moreover, the findings also suggest that intervention methods using the self-determination theory framework (i.e., autonomy and competence supportive) might be effective for individuals with chronic pain.