Using data from the National Comorbidity Survey--Replication, this study examined the timing of onset of self-report comorbid chronic nonarthritis pain and substance use disorders (SUDs) and characteristics associated with different onset patterns. Most individuals (58.2%; N = 351/632) report that the SUD preceded the onset of pain. Relative to those with SUDs prior to the onset of chronic pain, those experiencing pain first were less likely to have a drug use disorder, more likely to have head pain, to be younger at the onset of the first condition, and to have a shorter duration between condition onsets.