Background: This study aimed to assess the effectiveness and safety of transscleral microcyclophotocoagulation (µCPC) in patients with glaucoma for eighteen consecutive months. Methods: Sixty-one patients (64 eyes) with primary and secondary glaucoma were enrolled to undergo µCPC (diode laser FOX 810, A.R.C. Laser, Nuremberg, Germany). The primary outcome measures were intraocular pressure (IOP) reduction, success rates, glaucoma medication use, and visual acuity after µCPC. An IOP reduction of 20% compared to the baseline value without re-intervention was considered a successful treatment. Complete success was defined as cessation of antiglaucoma medications. Secondary outcome measures included intraoperative and postoperative complications. Measurements were performed preoperatively and at the first week, and 1, 3, 6, 12, and 18 months postoperatively. Results: The mean ± SD values of IOP preoperatively at 1 day, 1 week, 1, 3, 6, 12, and 18 months postoperatively were 25.1 ± 8.4 mmHg, 17.3 ± 4.5 mmHg (p< 0.001), 16.5 ± 6.1 mmHg (p< 0.001), 20.5 ± 8.3 mmHg (p< 0.001), 17.1 ± 6.2 mmHg (p< 0.001), 18.0 ± 7.1 mmHg (p< 0.001), 15.8 ± 3.2 mmHg (p< 0.001), and 17.0 ± 5.9 mmHg (p< 0.001), respectively. The mean IOP at the last follow-up was reduced by 32.5%. The decrease in the number of antiglaucoma medications was statistically significant at each follow-up visit compared to the baseline. The qualified success rate was 38.5%. Two patients at 18-month follow-up did not require the use of antiglaucoma medications—complete success rate—3.1%. During the follow-up period, twenty-five eyes (39.1%) that required retreatment due to nonachievement of the target IOP were considered as failures. Eleven patients (12 eyes—18.8%) were lost to follow-up. A total of 26 patients (27 eyes) were evaluated 18 months after µCPC. Hypotony was observed in one patient (1.6%) and uveitis in two patients (3.1%) after the procedure. There were no other significant intraoperative or postoperative complications observed. Conclusions: The µCPC is well tolerated and safe for reducing IOP in glaucoma patients in medium-term follow-up; however, success is moderate. Randomized, larger studies are needed to confirm the obtained results.