To determine the effect of low-intensity, long-wavelength red light therapy (LLRT) on the inhibition of myopia progression in children. A retrospective study was conducted. One hundred and five myopic children (spherical equivalent refractive error [SER] -3.09±1.74 dioptres [D]; mean age, 9.19±2.40years) who underwent LLRT treatment (power 0.4mW, wavelength 635nm) twice per day for 3min each session, with at least a 4-h interval between sessions, and a control group of 56myopic children (SER -3.04±1.66D; mean age, 8.62±2.45years) were evaluated. Both groups wore single-vision distance spectacles. Each child returned for a follow-up examination every 3months after the initial measurements for a total of 9months. At 9months, the mean SER in the LLRT group was -2.87±1.89D, significantly greater than that of the control group (-3.57±1.49D, p<0.001). Axial length (AL) changes were -0.06±0.19mm and 0.26±0.15mm in the LLRT group and control group (p<0.001), respectively. The subfoveal choroidal thickness changed by 45.32±30.88μm for children treated with LLRT at the 9-month examination (p<0.001). Specifically, a substantial hyperopic shift (0.31±0.24D and 0.20±0.14D, respectively, p=0.02) was found in the 8-14year olds compared with 4-7year old children. The decrease in AL in subjects with baseline AL >24mm was -0.08±0.19mm, significantly greater than those with a baseline AL ≤24mm (-0.04±0.18mm, p=0.03). Repetitive exposure to LLRT therapy was associated with slower myopia progression and reduced axial growth after short durations of treatment. These results require further validation in randomised controlled trials.