A 31-year-old woman infected with severe acute respiratory syndrome coronavirus 2 (SARS‑CoV‑2) at 33-weeks pregnant was subject to cesarean delivery due to a worsening respiratory condition. On the fourth day of illness, the patient was placed on a ventilator, with extracorporeal membrane oxygenation (ECMO) treatment initiated on the ninth day. Passive range of motion (ROM) training started on the day 33 of illness. She was weaned off ECMO on day 55 of illness and taken off of the ventilator on day 8. The tracheostomy tube was replaced with a speech cannula on day 87 of illness, at which time the patient began to complain of pain during passive ROM training. Plain X-ray photography and computed tomography (CT) showed ossification around the bilateral shoulder and hip joints, as well as on medial thighs, accompanied by an alkaline phosphatase (ALP) value of 942 U/L. She was subsequently diagnosed with heterotopic ossification, after which passive ROM training was changed to protective ROM training, in addition to treatment with indomethacin farnesyl and etidronate disodium. The patient was transferred to our hospital on day 122 of illness for the purpose of continuing rehabilitation. On day 155 of illness, ossification decreased on the medial thighs, according to CT. She was able to walk independently indoors and was discharged home on day 181 of illness. This case demonstrates the importance of checking the ALP levels and palpating the periarticular area in patients infected with SARS‑CoV‑2 before initiating passive ROM training, as well as being aware of any pain experienced during training. In the case of any abnormalities, assessing the ossification around the joints of extremities by imaging examination is a priority.