To evaluate the safety and efficacy of photorefractive intrastromal corneal crosslinking (CXL) in low myopia.Ruhr University Eye Hospital, Bochum, Germany.Prospective case series.Healthy eyes with myopia or myopic astigmatism had photorefractive intrastromal CXL using the Mosaic system to apply ultraviolet-A (UVA) 365 nm (30 mW/cm2) irradiance (total calculated UVA dose of 10 J/cm2 or 15 J/cm2) with riboflavin 0.1% solution. Efficacy was determined by the change in the manifest refraction spherical equivalent (MRSE), uncorrected distance visual acuity (UDVA), and corneal curvature. Safety was determined by the corrected distance visual acuity (CDVA), slitlamp biomicroscopy, endothelial cell count, and adverse events.Twenty-six eyes of 14 patients with a mean age of 30.8 years ± 9.3 (SD) were included. There were statistically significant improvements in UDVA 1, 3, and 6 months postoperatively (all P < .001). A significant improvement in CDVA was observed (P = .02). Improvements in the mean manifest sphere and MRSE versus baseline were noted at all visits (P < .001), with a mean change of 0.99 ± 0.47 diopter (D) and 0.97 ± 0.48 D, respectively, by 6 months postoperatively. Significant reductions in corneal curvature versus baseline occurred at all follow-up visits (all P < .05). At 1 month, there were no significant changes in the endothelial cell density (P = .282) or number of cells (P = .069). No safety issues or complications were reported.The findings show that patterned CXL using a custom CXL system is safe and effective for reducing myopic refractive error.