Light-grown broad bean (Vicia faba L.) seedlings were subjected to different intensities of UV-B radiation (0, 0.05, 0.15, 0.45, 0.90, 1.45 and 1.98 W m⁻²) for 7 h under photosynthetically active radiation (70 μmol m⁻² s⁻¹) and then exposed to He–Ne laser (632.8 nm, 5.43 mW mm⁻²) radiation for 5 min or red light radiation for 4 h without ambient light radiation. When He–Ne laser radiated leaves were treated using lower intensity UV-B, the activities of superoxide dismutase (EC 1.15.1.1), ascorbate peroxidase (EC 1.11.1.11) and catalase (EC 1.11.1.6) improved significantly. Moreover, the UV-B–injured plants treated with laser light recovered faster from UV-B treatment because the concentration of malondialdehyde and the rate of electrolyte leakage from leaf disks reached control levels (no UV-B or laser treatment) early compared with those exposed only to ambient light or in dark conditions. Laser treatment, however, had no repair effect on seedling damage induced by higher UV-B radiation (1.45 and 1.98 W m⁻²), even with higher laser flux rates and longer laser treatment. In addition, the red light treatment had no repair effect on UV-B–induced damage. Meanwhile, the long-term physiological effect of He–Ne laser treatment on UV-B damaged plants was presented and evaluated. The results showed that the laser had a long-term positive physiological effect on the growth of UV-B–damaged plants. With the exception of the severe damage caused by higher UV-B radiation, a laser with the proper flux rate and treatment time can repair UV-B–induced damage and shorten the recovery time.