PurposeThis study aimed to evaluate the impact of four cross-institutional teaching enhancement projects (TEPs), a relatively new form of professional collaboration. The focus is on the impact at departmental, institutional and cross-institutional levels because such impact is the main reason for establishing cross-institutional TEPs.Design/methodology/approachA professional capital framework guided the examination of decisional and social capitals at departmental, institutional and cross-institutional levels. A theory-of-change method was adopted to collect data from 35 sets of documents, 22 project members and 65 stakeholders.FindingsThe authors found five forms of impact, showing the development of decisional and social capitals mostly at institutional and cross-institutional levels, whilst signaling the relatively weak impact at departmental levels. Therefore, the values of cross-institutional TEPs have not been fully realized and future endeavors need to better utilize the capitals in programs.Originality/valueFew studies evaluated the impact of large-scale, cross-institutional TEPs. The authors offered new contributions by gauging the impact of these under-explored forms of complex professional collaborations.