BACKGROUND/OBJECTIVE: Management of concomitant cataract and glaucoma depends on the stage of glaucoma and the patients situation. There are different surgical options for handling visually significant cataract and mild-to-moderate open-angle glaucoma (OAG). We aimed to compare the one-year results of phacoemulsification alone versus phacoviscocanalostomy in these patients. SUBJECTS/METHODS: This was a parallel-arm, single-masked, randomized-controlled trial, conducted at Farabi Eye Hospital, Tehran, Iran between January 2016 and January 2018. We enrolled 89 eyes from 89 patients with mild-to-moderate primary OAG or pseudoexfoliative glaucoma (PEXG) with visually significant age-related cataract. They randomly underwent phacoemulsification alone (n = 44) or combined phaco-viscocanalostomy (n = 45). All patients had a 12-month follow-up period, and the mean intraocular pressure (IOP), the number of antiglaucoma medications, and complete and qualified success rates were compared. RESULTS: After the 1st and 3rd months, the mean IOP showed significantly decreased in the phaco-visco group compared to the phaco group (P < 0001 and P = 0.004, respectively), but it was not statistically significant at 6th and 12th months (P = 0.540 and P = 0.530). The need for antiglaucoma medication and the complete and qualified success rates were significantly in favour of the phaco-visco group in all postoperative visits (P < 0.05). CONCLUSIONS: Although both phacoemulsification alone and phacoviscocanalostomy procedures can be considered for patients with mild-to-moderate OAG, we found better success rates using phacoviscocanalostomy. Therefore, if the surgeon is an expert in performing this technique, this non-penetrating procedure can be applied in patients with visually significant cataract and earlier stages of OAG, especially in patients with PEXG.