Thyroid surgeries are performed worldwide for various indications. In the past complications of thyroid surgeries were reported more than 24%. With an increase in accuracy in Cytological reporting, non-invasive radiological investigations to know the extent of the tumor and infiltration of malignant tumors, the complications are reduced to less than 4%. AIM: To evaluate the predictability of pre-operative investigations in preventing the post-operative complications of thyroid surgery. MATERIALS AND METHODS:A prospective study conducted on 86 patients by investigating before thyroid surgeries with FNAC, ultrasonography, CT scan, X-ray Neck lateral view, MRI, 2D ECHO of Cardia, isotope scanning, video laryngoscopy and thyroid function tests. Demographic characteristics of the patients and indications for thyroid surgeries were used to predict the postoperative complications. Post-operative investigations included serum calcium levels, Thyroid function tests and serum Electrolyte levels to diagnose the complications. RESULTS: sensitivity of FNAC was 93.33%, ultra sound Neck was 92.83%, serum calcium was 89.16%, in thyroid function tests it was 77.66%. With X-Ray Neck the specificity was 57.66%, CT scan was 44.50%, MRI was 15%, and isotope study was 30.6%, Doppler study was 33.83% and 2DEcho was 27.83%. Pre-operative assessment was Airway obstruction 3.48%, hematoma formation 4.65%, RLN palsy 3.48%, Hypocalcaemia 33.72%, wound infection 4.65% were the complications encountered. CONCLUSIONS: Thorough investigations prior to surgery of thyroid, proper selection of the surgical procedure, tumor location knowledge, understanding the pathophysiology of the thyroid disease and type of anesthesia gives confidence to the surgeon and avoids complications. The methods applied in the present study had a definitive role in preventing hypocalcaemia with an incidence of 33.72% and RLN palsy 3.48%. These were added upon by the experience of the operating surgeon.