Evidence suggests that cumulative somatic complaints predict health care utilization in college students. The symptom perception hypothesis and the response expectancy theory are 2 theories concerning the generation of somatic complaints. The symptom perception hypothesis suggests that negative affect influences daily somatic complaints, whereas the response expectancy theory surmises somatic complaint generation relates to response expectancies. Some evidence suggests that understanding the complex interplay of these factors may enhance prediction of daily somatic complaints. This study examines the combined effects of state negative affect, trait negative affect, and response expectancies in predicting daily somatic complaints. A total of 95 college students took part in a 2-part study composed of 1 in-lab session followed by completion of up to 7 daily diaries. Results show that state negative affect, trait negative affect, and response expectancies all uniquely predict daily somatic complaints. Our results support a cognitive-affective basis for somatic complaints and suggest future research integrating biopsychosocial factors may be useful in increasing our understanding. Furthermore, our results suggest potential intervention targets when counseling college students experiencing somatic complaints without physical origins.