Bone mass is maintained by a balance between bone formation by osteoblasts and resorption by osteoclasts. Calvarial thinning can occur because of various factors. However, no previous studies have described bilateral temporal thinning (BTT) of the skull. This report presents a case of a squamous part of the bilateral temporal bone in a patient with alcohol-induced liver cirrhosis. This is the first case of BTT exhibiting an appearance similar to that of bilateral parietal thinning (BPT) in a patient with osteoporosis caused by liver cirrhosis. Although the precise pathogenic mechanism underlying thinning of the squamous part of the temporal bone remains unclear, osteoporosis associated with diploë is presumed to have contributed to its development in this patient, and BTT is considered a variant of BPT.