Objectives: Mugger crocodiles breed twice in a year under captivity resulting in over population; requiring birth control measures. As the testis and vas deferens are intra-abdominal, the efficacy of surgical ablation of sulcus spermaticus that transport the sperm during copulation, on the dorsal surface of the phallus was assessed. Methods: Twelve male crocodiles weighing between 140 to 230 kg were immobilized and anaesthetized with a combination of xylazine-ketamine at the dose rate of 1.5 and 20 mg/kg body weight respectively. Under aseptic precautions the phallus was retracted through cloacal slit as the animal was positioned on dorsal recumbency. The mucous membrane guarding the groove and floor were resected to ablate the sulcus spermaticus and the mucous membrane on either side was sutured. After 6 to 8 months randomly 6 crocodiles were immobilized and the phallus was examined, which revealed no signs of regeneration of the groove. Conclusion: The study revealed that ablation of sulcus spermaticus could be followed as a birth control surgery in male mugger crocodiles without affecting the welfare and breeding behavior.