Activity pacing has been associated with both improved and worsened symptoms, and its role in reducing disability among patients with long-term conditions has been questioned. However, existing studies have measured pacing according to unidimensional subscales, and therefore the empirical evidence for pacing as a multifaceted construct remains unclear. We have developed a 26-item Activity Pacing Questionnaire (APQ-26) for chronic pain/fatigue containing 5 themes of pacing: activity adjustment, activity consistency, activity progression, activity planning, and activity acceptance. Objective: To assess the associations between the 5 APQ-26 pacing themes and symptoms of pain, physical fatigue, depression, avoidance, and physical function. Methods: Cross-sectional questionnaire study design. Data analyzed using multiple regression. Participants: A total of 257 adult patients with diagnoses of chronic low back pain, chronic widespread pain, fibromyalgia, and chronic fatigue syndrome/myalgic encephalomyelitis. Results: Hierarchical multiple regression showed that activity adjustment was significantly associated with increased physical fatigue, depression, and avoidance, but decreased physical function (all Ps≤0.030). Activity consistency was associated with decreased pain, physical fatigue, depression, and avoidance, but increased physical function (all Ps≤0.003). Activity planning was associated with reduced physical fatigue (Ps=0.025) and activity acceptance was associated with increased avoidance (Ps=0.036). Conclusions: Some APQ-26 pacing themes were associated with worse symptoms and others with symptom improvement. Specifically, pacing themes involving adjusting/reducing activities were associated with worse symptoms, whereas pacing themes involving undertaking consistent activities were associated with improved symptoms. Future study will explore the causality of these associations to add clarification regarding the effects of pacing on patients' symptoms.