It is not possible to sleep on one’s side after a pelvic fracture. Pelvic fractures include a variety of types, including sacral fractures, fractures of the iliac wings, fractures of the superior and inferior branches of the pubic bone and of the sciatic branch, and, in more serious cases, a combination of multiple fractures. Some are associated with vertical instability, some with rotational instability, and in severe cases, with vertical and rotational instability in both directions. Regardless of the type of fracture, for patients with vertical and rotational multidirectional instability, i.e. multiple pelvic fractures, emergency surgical treatment is required. In contrast, fractures of the iliac wing, sacrum, or superior and inferior branches of the pubic bone that are simply undisplaced can be treated conservatively. If conservative treatment is used, the most common way to obtain fracture healing is by lying flat on your back. In order to prevent pressure sores, you can put a bedsore pad on the mattress, or use thinner soft pillows alternately on the waist, and mildly help the patient to turn on his/her side to avoid pressure sores, but you should never sleep on your side, because the weight of the body in the side-lying position may aggravate the displacement of the pelvic fracture, and therefore you should not sleep on your side after a pelvic fracture.