Present study was planned to investigate the cause of postpartum true anoestrus in buffaloes during summer through the analysis of hemato-biochemical and endocrinological profile of anoestrus buffaloes. Blood samples were collected from 50 buffaloes belonging to two groups i.e. cyclic (n=10), and summer anoestrus buffaloes (n=40) animals respectively. The samples were analysed for haematological parameters including total erythrocytes count (TEC), total leukocytes count (TLC), haemoglobin (Hb), packed cell volume (PCV), erythrocyte sedimentation rate(ESR), mean corpuscular haemoglobin concentration(MCHC), biochemical parameters viz., glucose, total protein, albumin, total cholesterol, urea, creatinine, alkaline phosphatase, alanine amino transaminaseand aspartate transaminase, calcium, phosphorus, manganese, zinc, copper cobalt and hormones of the plasma sample viz., progesterone, estradiol tri-iodothyronine (T3) thyroxine (T4) and cortisol using commercially available kits. The results revealed that Hb and MCH varied significantly (P<0.05) between the groups and other haematological parameters did not vary between two groups. In biochemical parameters glucose, total protein, albumin and total cholesterol were significantly (p<0.05) lower in anoestrus buffaloes than normal cyclic buffaloes and the progesterone, estradiol, tri-iodothyronine and the cortisol concentration varied significantly (P<0.05)between two groups. It can be concluded that variation in some hematobiochemical and hormonal levels might be the cause of the anoestrus during summer stress in buffaloes.