Objectives This is the fi rst assessment of effi cacy and safety of the Er:YAG laser in the treatment of stress urinary incontinence. The aim of this study was to assess the short-term outcome of a non- invasive laser treatment for mild-to-severe stages of this condition and to check its applicability in different body mass index and age groups. Methods A prospective cohort, single-center study at the Ob/Gyn Clinic, Zagreb, Croatia recruited a consecutive sample of 73 female patients suffering from stress urinary incontinence. The procedure was performed with a 2940-nm Er:YAG laser (XS Dynamis, Fotona, Slovenia) designed to achieve heating up of vaginal mucosa to around 60 ° C, 500 – 700 μ m in depth. Results The score in the International Consultation on Incontinence Questionnaire- Urinary Incontinence Short Form was reduced to a median of 46% (95% confi dence interval 33 – 67% ; p 0.001). The reduction was signifi cantly higher in women with normal body mass index (67%) than in overweight women (25%), as well as in women younger than 39 years (100%) compared with those older than 60 years (8%) ( p 0.001). No serious adverse events were noticed. Conclusion This study of Er:YAG laser therapy in women has demonstrated a clinically relevant, short-term improvement of stress urinary incontinence, with minimal adverse events of a transient nature.