Objectives We conducted two studies to examine the dimensions, internal consistency reliability estimates, and potential correlates of the Depression Anxiety Stress Scales—21 (DASS‐21; Lovibond & Lovibond, 1995). Method Participants in Study 1 included 887 undergraduate students (363 men and 524 women, aged 18 to 35 years; mean M age = 19.46, standard deviation SD = 2.17) recruited from two public universities to assess the specificity of the individual DASS‐21 items and to evaluate estimates of internal consistency reliability. Participants in a follow‐up study (Study 2) included 410 students (168 men and 242 women, aged 18 to 47 years; M age = 19.65, SD = 2.88) recruited from the same universities to further assess factorial validity and to evaluate potential correlates of the original DASS‐21 total and scale scores. Results Item bifactor and confirmatory factor analyses revealed that a general factor accounted for the greatest proportion of common variance in the DASS‐21 item scores (Study 1). In Study 2, the fit statistics showed good fit for the bifactor model. In addition, the DASS‐21 total scale score correlated more highly with scores on a measure of mixed depression and anxiety than with scores on the proposed specific scales of depression or anxiety. Coefficient omega estimates for the DASS‐21 scale scores were good. Conclusions Further investigations of the bifactor structure and psychometric properties of the DASS‐21, specifically its incremental and discriminant validity, using known clinical groups are needed.