Objective: To assess the efficacy and safety of combined surgery (manual small incision cataract surgery [mSICS] and cyclodialysis) in eyes with cataracts and advanced glaucoma or uncontrolled ocular hypertension. Method: Retrospective study of 343 consecutive eyes that underwent mSICS and cyclodialysis. All surgeries were performed by experienced surgeons during 2017 and 2018. To evaluate the efficacy and safety of the procedure, we used a control group of 53 consecutive eyes that only underwent cyclodialysis during the same period. In both groups, the change in intraocular pressure (IOP), glaucoma control medications, best-corrected visual acuity (BCVA), complications, and reinterventions were evaluated and compared. Results: The decrease in IOP was greater in the combined surgery group (p = 0.01). The need for medications to control glaucoma was lower in the combined surgery group (p = 0.07) and, in the same way, BCVA was better in this group (p = 0.05). The frequency of complications was lower in the cyclodialysis group (p = 0.03). The frequency of reoperations was lower in the combined surgery group (p <0.01). In both groups, most reoperations were procedures to control IOP. Success and graded success were higher in the combined surgery group (p <0.01). Conclusions: Combined mSICS surgery is effective and relatively safe in eyes with cataracts and advanced glaucoma or with uncontrolled ocular hypertension. It is a low-cost procedure that represents a good alternative in developing countries.