Background: We report the effect of micropulse laser trabeculoplasty (MLT) in the intraocular pressure (IOP) of patients with uncontrolled open-angle glaucoma (OAG). Materials and Methods: In this retrospective review, 30 eyes with OAG were treated with a single session of MLT at the Vista Clinic in Lima Peru. We used a 532 nm frequency doubled Nd: YAG laser to 360 degrees of the trabecular meshwork with a power of 1000 mW, 15% of the duty cycle, and 300 ms of exposure. The IOP was measured at baseline and at 1 day, 1 week, 3 months, and 6 months post-treatment and were followed up for one last control. Results: The mean baseline IOP was 15.6 mmHg and in the last control was 12.8 mmHg, mean follow-up time of 19 months (+/-10 standard deviation [SD]). The mean reduction of IOP in the 1(st) day was 1.6 mmHg (+/-2.6 SD) and 1.2 mmHg (+/-3.3 SD) in the last follow-up. The mean percentage of IOP reduction was 17.9% and 7 eyes (40%) had IOP reduction >20%. No statistical significant difference in relation to demographic characteristics of the patients. The greatest reduction was achieved in the 1(st) day with a median of 2.00 (P < 0.001). A tendency to achieve a higher reduction of IOP in patients with higher baseline IOP was found but was not statistically significant. No adverse reactions occurred. Conclusions: MLT slightly reduced the IOP in a few patients with uncontrolled OAG for a very short time and may not be suitable for these patients.