Anaerobic fungi were orally dosed to lactating buffaloes to study their effect on the digestibility of a diet (composed of 50% wheat straw and 50% concentrate along with six kg maize green/animal/day), rumen fermentation patterns and milk production. Group I (control) was administered with fungus-free anaerobic broth, while group II and III were administered with Orpinomyces sp. C-14 or Piromyces sp. WNG-12 (250 ml; 3-5 days of growth/animal/ week), respectively. Milk production was higher in group II and III (8.42 and 8.48 kg/d) than in the control (8.03 kg/d) with virtually the same feed intake (i.e. 11.50 and 10.62 and 11.79 kg, respectively). There was an increase of 6% fat-corrected milk yield/animal/day in group II and III, respectively compared to the control. The milk fat was higher in the fungal culture administered groups than in the control group. The digestibility of dry matter, crude protein, neutral detergent fibre, acid detergent fibre, cellulose and digestible energy also increased significantly in group II and III. The pH and ammonia nitrogen were lower, whereas total volatile fatty acids, total nitrogen, trichloroacid precipitable nitrogen and number of zoospores/ml of rumen liquor were higher in group II and III when compared to the control. Hence, it can be stated that rumen fungi can be used as a direct-fed microbial in lactating buffaloes, to enhance the digestibility of wheat straw based diets leading to higher production.