Patients frequently display behaviors during procedures that may be pain related. Clinicians often rely on the patient's demonstration of behaviors as a cue to presence of pain. The purpose of this study was to identify specific pain-related behaviors and factors that predict the degree of behavioral responses during the following procedures: turning, central venous catheter insertion, wound drain removal, wound care, tracheal suctioning, and femoral sheath removal. Prospective, descriptive study. Multiple units in 169 hospitals in United States, Canada, England, and Australia. A total of 5,957 adult patients who underwent one of the six procedures. None. A 30-item behavior observation tool was used to note patients' behaviors before and during a procedure. By comparing behaviors exhibited before and during the procedure as well as behaviors in those with and without procedural pain (as noted on a 0-10 numeric rating scale), we identified specific procedural pain behaviors: grimacing, rigidity, wincing, shutting of eyes, verbalization, moaning, and clenching of fists. On average, there were significantly more behaviors exhibited by patients with vs. without procedural pain (3.5 vs. 1.8 behaviors; t = 38.3, df = 5072.5; 95% confidence interval, 1.6-1.8). Patients with procedural pain were at least three times more likely to have increased behavioral responses than patients without procedural pain. A simultaneous regression model determined that 33% of the variance in amount of pain behaviors exhibited during a procedure was explained by three factors: degree of procedural pain intensity, degree of procedural distress, and undergoing the turning procedure. Because of the strong relationship between procedural pain and behavioral responses, clinicians can use behavioral responses of verbal and nonverbal patients to plan for, implement, and evaluate analgesic interventions.