According to clinical and experimental research, nonverbal expressions of pain are key components in its assessment. Theoretical formulations of pain specify that various contextual influences, or factors unrelated to the pain experience (e.g., patients’ age), significantly moderate observers’ interpretation of nonverbal pain expressions. Such contextual factors have been found to alter observers’ assessment of younger adults’ pain; however, the systematic study of such influences within the context of the older adult has been limited. The purpose of this study was to examine the effects of contextual factors on decoding facial pain expressions in both younger and older adults. A total of 165 participants (82 nursing students and 83 non-nursing students) were recruited. Participants were randomly assigned to one of three priming conditions: (1) information about the possibility of secondary gain [misuse]; (2) information about the frequency and undertreatment of pain in the older adult [undertreament]; or (3) neutral information [control]. Subsequently, participants viewed eight videos of older adults and eight videos of younger adults expressing pain nonverbally. Following each video, participants rated their perception of the individual’s pain intensity, unpleasantness, and condition severity as well as their willingness to help and sympathy, patient deservingness of financial compensation, and how negatively/positively they feel towards the individual (i.e., valence). Mixedmodel analyses were conducted to determine the main effects and interactions across prime conditions (misuse vs. undertreatment vs. control), observer type (nursing and non-nursing students), and stimulus persons’ age (older vs. younger stimulus persons) on observers’ estimates. Results demonstrated that observers’ ratings varied as a function of stimulus persons’ age, observer type, and informational priming condition. More specifically, observers ascribed greater levels of pain and rated differently (e.g., greater sympathy) older stimulus persons compared to younger. Observer type and stimulus persons’ age also interacted to influence observers’ ratings. That is, in comparison to nonnursing students’ ratings of younger adults, nursing student endorsed higher ratings of younger adults’ pain and compensation deservingness. Additionally, priming conditions interacted with both observer type and stimulus persons’ age to moderate observers’ valence towards the stimulus person. In general, this interaction demonstrated that observers primed with information about the undertreatment of pain in older persons reported more positive valence towards older patients and priming observers with information about the misuse of the health care system attenuated their valence ratings towards younger patients. Finally, the undertreatment of pain in older adults prime also influenced observers’ pain estimates indirectly though observers’ valence towards the stimulus persons. More specifically, observers in the undertreatment prime condition reported more positive valence towards stimulus persons. The higher valence subsequently resulted in higher ratings of pain and affected other ratings (e.g., willingness to help) of both younger and older patients. In summary, results support the influence of contextual features in interpreting others’ pain. Findings from this study add specificity to the theoretical formulations of pain by clarifying the role of several contextual factors on observers’ interpretations of nonverbal pain expressions of older and younger persons.