Abstract: Objective To evaluate the efficacy and safety of long pulse 1064 nm Nd:YAG laser therapy in the treatment of onychomycosis of the toenails. Methods A total of 104 patients with onychomycosis (461 toenails) were divided by age into ≥60 years group and <60 years group, and each group was further divided into subgroups according to Scoring Clinical Index of Onychomycosis (SCIO) scoring and the location of the compromised toenails. All the toenails were treated with 10 to12 sessions of long pulse 1064 nm Nd:YAG laser therapy at the interval of 1 week. All the patients were followed up for 48 weeks after the initial treatment to assess the clinical efficacy and adverse reactions. Results The overall clinical response rate in these patients was 72.5% by the end of the 48-week follow-up. In patients aged <60 years, the clinical response rate and mycological cure rate were significantly higher than the rates in patients aged ≥60 years (P<0.05). No significant differences were observed in the response rates between different SCIO subgroups (P>0.05); the 2nd to 4th toenails showed better outcomes after the therapy than the 1st and 5th toenails (P<0.05). No adverse reactions related with the therapy were recorded in these patients. Conclusion Long pulse 1064 nm Nd:YAG laser is an effective and safe approach for treatment of onychomycosis of the toenails.