Objective. Roux-en-Y gastric bypass (RYGB) is an independent risk factor for moderate hypocalcaemia and may lead to the development of resistant hypocalcaemia following thyroid surgery. Subject and Results. A 35-year old female patient was referred to our hospital by her family physician for treatment of resistant hypocalcaemia. The patient underwent RYGB three years ago and a total thyroidectomy for a benign thyroid nodule one year ago. Calcitriol, calcium carbonate, magnesium oxide, and ergocalciferol therapeutic dosages were incremented. Despite dosage increments, the desired calcium levels were not achieved. In the sixth month after admission to our hospital, pancrelipase was added to patient’s treatment scheme. On the following visit, a good calcium increase had been achieved. Conclusion. This report presents a case history of RYGB and resistant hypocalcaemia, which developed after thyroid surgery and positively responded to pancrelipase treatment.