PurposeWe aimed to evaluate the relationship between temporal muscle thickness and GH/IGF-1 elevation and the effect of acromegaly treatment on temporal muscle thickness. MethodsPatients with acromegaly and healthy controls were included in the study. While laboratory parameters, clinical findings and temporal muscle thickness of acromegaly patients at the time of diagnosis and one year after treatment were evaluated, laboratory parameters and temporal muscle thickness of healthy controls were evaluated only during the period when they were included in the study. Temporal muscle thickness was measured using pituitary MRI. Temporal muscle thickness of patients with acromegaly was compared with healthy controls. We also evaluated how temporal muscle thickness changes with treatment in patients with acromegaly and the association between laboratory parameters and temporal muscle thickness. ResultsIn patients with acromegaly, measurements of left, right, and mean temporal muscle thickness at the time of diagnosis were found to be significantly higher than those of healthy controls' measurements at the time of their inclusion in the study (p = 0.007, p = 0.014 and p = 0.018, respectively). However, no significant difference was found when comparing the temporal muscle thickness of the 1st year of acromegaly treatment with the temporal muscle thickness of healthy controls at the time of their inclusion in the study (p = 0.155, p = 0.189, p = 0.198, respectively). In addition, a significant decrease was detected in the left, right and mean temporal muscle thicknesses of patients with acromegaly before and after treatment. While the temporal muscle thickness at the time of diagnosis was thicker in patients with acromegaly receiving surgical + medical treatment than in patients receiving exclusively surgical treatment, statistical significance was only found in the left temporal muscle thickness (p = 0.042). ConclusionTemporal muscle thickness was found to be associated with treatment modalities in patients with acromegaly.