This study aimed to evaluate the performance of the Sarana Makmur Dairy Farmers Cooperative (Koperasi Peternakan Sarana Makmur/KPSM) from the perspective of five institutional aspects, namely cooperative institutional aspects, business aspects, financial aspects, benefits to members, and benefits to society. The research was conducted at KPSM located in Cangkringan District, Sleman Regency, Special Region of Yogyakarta, in October 2025 using a descriptive quantitative approach. The study employed primary data obtained through interviews with key cooperative informants and secondary data derived from cooperative documents and reports. Cooperative performance was analyzed based on the Regulation of the Minister of Cooperatives and SMEs No. 21/Per/M.KUKM/IX/2015 and the Regulation of the Deputy for Institutional Affairs No. 04/Per/Dep.1/III/2018. The results showed that KPSM achieved a total performance score of 1,180, placing it in the “Good Quality” category with an AAB rating. The institutional, financial, and member benefit aspects demonstrated good to very good performance, reflecting sound governance, stable financial conditions, and tangible benefits for members’ welfare. However, the cooperative business aspect and benefits to society were assessed as moderately good and require further improvement, particularly in strengthening inter-member business linkages and optimizing the distribution of surplus. Overall, KPSM has functioned effectively as both an economic and social institution, although there remains room for improvement to enhance its competitiveness and long-term sustainability. Keywords: cooperative performance, dairy cooperative, institutional aspects, Sarana Makmur cooperative, Yogyakarta