Introduction: In peer assessment practices, several academic integrity issues often occur in female physical education students. Objective: This study aims to examine the relationship between positive mental health (PMH) and peer-assessment with integrity using a mixed-method study with an explanatory sequential design. Methodology: Quantitative PMH data were collected from 31 female students using the nine-item Positive Mental Health Scale, and academic integrity data in conducting peer-assessment were collected using the 24-item Peer-Assessment Academic Integrity Scale. Qualitative data were collected from six respondents using six semi-structured interview guidelines to explore respondents' experiences using PMH to conduct peer-assessment with integrity. Results: Spearman’s test proved a positive and significant correlation between PMH and peer-assessment with integrity (ρ = 0.634; sig. <0.001). In the thematic analysis, the PMH experience that helps female students carry out peer-assessment with integrity is: (1) stimulating motivation through constructive assessment, (2) managing emotions from various subjective pressures, (3) believing in one’s ability to remain objective at all times, and (4) rejecting compromise with various academic deviations. Discussion: These results provide an important note that lecturers need to pay attention to the mental health of their female students before allowing them to participate in peer assessment in order to avoid various assessment practices that are not conducted with integrity. Conclusions: Strengthening positive mental health can be an important strategy in improving academic integrity, especially in peer assessment.