Past research has suggested that dispositional cancer worry may be a key predictor of health behavior. The current study examined seven measures of dispositional cancer worry to see if they were significantly related (convergent validity), significantly different from similar but distinct traits (divergent validity), and capable of predicting cancer-relevant outcomes (predictive validity). Four hundred and eighty nine undergraduate students completed a survey measuring dispositional worry, dispositional cancer worry, and perceived cancer risk. Factor analysis identified four underlying dimensions that explained 67.3% of the variance in dispositional cancer worry: severity (42.8%), frequency (12.3%), psychological reactance (6.9%), and worry impact (5.3%). Four existing measures of dispositional cancer worry were found to represent each of these dimensions. In general, dispositional cancer worry measures were highly correlated with one another and only moderately correlated with measures of dispositional worry, supporting strong convergent and divergent validity. Hierarchical regression analyses revealed that dispositional cancer worry measures predicted significant variance in cancer-relevant outcomes above and beyond dispositional worry. The results of the current study support the notion that dispositional cancer worry and dispositional worry are distinct constructs. Furthermore, two dimensions of dispositional cancer worry (severity and frequency) seemed to have the strongest convergent, divergent, and predictive validity.