Background. Selective laser trabeculoplasty (SLT) is a safe and effective treatment modality for lowering intraocular pressure (IOP). Purpose. To determine the efficacy and safety of SLT among Ethiopian patients with primary open-angle glaucoma (POAG), pseudoexfoliation glaucoma (PXG), and ocular hypertension (OHT). Method. A prospective, nonrandomized interventional study was conducted at Menelik II Hospital, Ethiopia. Patients on antiglaucoma medication with uncontrolled IOP and those patients treated for the first time with 360 degrees of SLT were included. Success was defined as an IOP lowering of > 20% from baseline without repeat treatment. Result. A total of 95 eyes of 61 patients with a diagnosis of OAG and OHT were enrolled. The diagnosis was POAG in 55 (57.9%) eyes, PXG in 22 (23.2%) eyes, and OHT in 18 (18.9%) eyes. Seventy (73.7%) eyes were on medications, and 25 (26.3%) eyes were treated with laser as primary therapy. The mean (SD) baseline IOP and medication were 24.3 ± 2.5 mmHg and 1.29 ± 1.01, respectively. The one-year mean (SD) IOP reduction was 6.7 ± 4.2 mmHg and medication reduction was 0.26 ± 1.34. The overall IOP reduction at 12 months was 27.6%, and the success rate was 60%. The mean IOP (SD) reduction for patients who were treated for the first time with laser and on antiglaucoma medication was 6.5 ± 3.1 mmHg and 6.8 ± 2.8 mmHg, respectively. Post-SLT, patients experienced transient ocular pain, brow ache, headache, and/or blurring of vision in 31.6%, anterior chamber reaction in 36.8%, and IOP spike ≥ 6 mmHg in 11.6%. Conclusion. SLT is an effective and safe treatment modality for OHT, POAG, and PXG among Ethiopian patients either as a first-line treatment or as an adjunct to topical glaucoma treatment.