AIM: To investigate how body temperature (BT) affects choroidal thickness (CT) according to measurements taken with enhanced depth imaging optical coherence tomography (EDI-OCT).METHODS: In this prospective study, the CT of 41 healthy patients was measured hourly from 9∶00 to 17∶00 at the fovea (SF-CT), 500 μm nasal to the fovea(N-CT), and 500 μm temporal to the fovea (T-CT) using EDI-OCT.BT was also measured hourly from 9∶00 to 17∶00 using a non-contact infrared thermometer.Possible correlations between diurnal variations of CT and BT were evaluated.RESULTS: SF-CT values significantly differed between measurements at 9∶00 and 13∶00 (P=0.021), 9∶00 and 14∶00 (P=0.012), 9∶00 and 16∶00 (P=0.048), and 9∶00 and 17∶00 (P=0.002).N-CT values also significantly differed between measurements at 9∶00 and 13∶00 (P=0.004), though T-CT did not significantly vary during the 8h period (P >0.05 for all).CONCLUSION: CT is not significantly associated with hourly changes in BT from 9∶00 to 17∶00.