Background: The mini-Mental Adjustment to Cancer Scale is designed to assess psychological responses to cancer diagnosis and is widely used in research and clinical practice. Recent evidence demonstrates adequate convergent validity but inconsistent internal consistency and factor structure. This study aimed to provide a parsimonious factor structure with clinical utility. Methods: Repeated measures data were collected from 160 cancer patients (mixed illness type) at diagnosis and 3-month follow-up. Principal axis factoring with oblimin rotation was used. The number of factors was decided using parallel analysis. The resultant factors were compared against the recommended five-factor structure on internal consistency (Cronbach's alpha) and test-retest reliability and convergent validity (Pearson's correlation). Results: Parallel analysis suggested that a four-factor model optimally fits these data. Two of these - cognitive avoidance and fighting spirit - are equivalent to the original factor structure. Redistribution of the remaining items resulted in factors of cognitive distress and emotional distress. Internal consistency and test-retest reliability of the new four-factor structure are equivalent, but convergent validity is much improved overall when compared with a five-factor structure, with the exception of the fighting spirit factor. Conclusions: The revised four-factor structure represents a more psychometrically sound measure of psychological adjustment in the current dataset. Findings related to the larger cognitive distress factor are congruent with data from foreign-language validation studies. The brevity of this improved measure may make it easier to administer in the clinical setting.