People with chronic pain often report sleep of "poor quality." However, it is unclear what defines sleep quality and whether their sleep quality judgment is influenced by factors other than sleep. We purposively interviewed 17 participants with and without chronic pain and thematically analyzed their interview transcripts. Four salient criteria for judging sleep quality were (a) memories of night-time sleep disruptions, (b) feelings on waking and cognitive functioning during the day, (c) ability to engage in daytime physical and social activity, and (d) changes in physical symptoms (and pain intensity among participants with chronic pain). Sleep quality judgment is complex and involves retrospective decision making influenced by not only memories of the night but also how we feel and what we do during the day.