Cognitive impairment is a common consequence of mild stroke. Current performance-based assessments for mild stroke can detect mild impairments in executive function but lack alternate forms to be used as outcome measures. This study aimed to develop an alternate form of the Complex Task Performance Assessment (CTPA–Alt), a performance-based assessment of executive function, and to establish the alternate form reliability of the CTPA–Alt. A repeated-measures study was conducted with 26 community participants. Participants were screened for eligibility and administered both forms of the CTPA; administration order was alternated. Overall performance was significantly correlated (rs = .44, p = .03), but pattern of scoring differed by CTPA form and order of administration. Our results indicate that the CTPA forms were similar but that the specific tasks in each form were different. The CTPA may be used as an ecologically valid outcome assessment with further considerations.