Purpose: We developed the Goal Achievement Scale in Colleges of Education (GASCE) to address the lack of context-specific assessment tools for evaluating goal achievement in Nigerian colleges of education. Existing instruments fail to capture the unique challenges of these institutions, making a reliable and valid scale essential for assessing educational success. Design/methodology/approach: Using a descriptive survey research design, we developed and validated the GASCE through expert review, pilot testing, and statistical analyses. Our sample of 450 respondents from Nigerian colleges of education participated in exploratory factor analysis (EFA), graded response modeling (GRM-IRT), confirmatory factor analysis (CFA) and multiple group confirmatory factor analysis (MG-CFA). We assessed reliability using composite reliability and validated construct and criterion-related validity through correlations with external goal achievement measures. Findings: CFA confirmed a six-factor structure -- critical thinking, committed teaching, high motivation, intellectual fitness, professional fitness and social fitness -- with strong model fit indices. Reliability testing showed high internal consistency (Omega alpha: 0.845-0.919). MG-CFA confirmed measurement invariance across academic and non-academic staff ([delta]comparative fit index < 0.015, [delta]root mean square error of approximation < 0.010), while criterion-related validity was supported by significant correlations with external measures. Research limitations/implications: While the sample size supports validation, it may not fully represent all Nigerian colleges of education. Future research should expand the sample and incorporate objective performance data for further validation. Practical implications: The GASCE provides policymakers, educators and administrators with a robust tool to assess and improve educational performance, facilitating targeted interventions and efficient resource allocation. Originality/value: The GASCE fills a critical gap in educational assessment by offering a reliable, context-specific tool for Nigerian colleges of education. It enables comprehensive evaluation of goal achievement, supporting continuous improvement in teacher education programs across Nigeria.