Objective: This study was conducted to investigate the effect of feeding a high proportion concentrate containing tofu waste on nutrient consumption, milk production, body condition (BC) score and length of postpartum mating (PPM) period of dairy goats. Methodology: Data were collected from 30 lactating goats on small farms in the Sleman region of the Yogyakarta province in Indonesia. The goats were fed diets consisting of Calliandra calothyrsus and wheat pollard with (Farm B, Diet B) or without (Farm A, Diet A) tofu waste. The proportion of concentrates in the diets on a dry matter (DM) basis was 20 and 55% for Diet A and Diet B, respectively. Data for feed and nutrient consumption, milk production, BC score and length of PPM period were collected. All data were statistically analyzed by t-test. Results: Feeding a high proportion concentrate containing tofu waste significantly (p<0.05) decreased DM and crude protein (CP) intake but did not affect the consumption of crude fiber and total digestible nutrients. High proportion concentrate significantly (p<0.05) lengthened PPM period but no effect on milk production. Long PPM period presumably associated with the presence of tofu waste in high concentrate diet. Conclusion: Diets containing high proportion concentrate with tofu waste did not affect milk production or BC score but lengthened the PPM period. Thus, the proportion of tofu waste can be reduced to avoid negative effects of phytoestrogens contained in the tofu waste on reproductive performance.