A six-year-old Holstein Friesian crossbred cow was brought to the Large Animal Gynaecology ward, Madras Veterinary College Teaching Hospital for Artificial Insemination with the history of cloudy vaginal discharge. On rectal examination, the uterus was distended with fluid, On real-time ultrasonography, the ovaries were diagnosed with multiple large anechoic follicles in the right ovary and two large follicles in the left ovary. The uterine fluid was aspirated and found to be watery and cloudy. The cow was diagnosed with mucometra due to follicular cyst and treated with 20µg GnRH intramuscularly. Re-examination after 10 days showed the presence of corpus luteum (CL) on the left ovary and persistence of the cysts on the right ovary. GnRH treatment was repeated along with cloprostenol sodium (500µg I/M) for lysis of the corpus luteum. The condition persisted post treatment as the uterus was non responsive due to the severity and long-established condition. The treatment was unsuccessful mainly due to the thickening and unresponsiveness of the endometrium with longstanding persistence of follicular cyst and the prognosis was guarded.