AIM: To evaluate and compare the incidences of ocular hypertension and severe intraocular pressure (IOP) elevation after posterior subtenon injection of triamcinolone acetonide (PSTA) for various diseases. METHODS: Totally 179 eyes that had received PSTA for diabetic macular edema (n=108), pseudophakic cystoid macular edema (n=20), branch retinal vein occlusion (n=16), central retinal vein occlusion (CRVO, n=14), choroidal neovascularization (n=14) or noninfectious uveitis (n=7) were retrospectively enrolled. The primary outcomes included ocular hypertension defined as an IOP>21 mm Hg, and severe IOP elevation defined as a rise of 10 mm Hg or more in IOP compared with baseline. Cox regression models were used to analyze the hazard ratios (HRs) among different diseases. RESULTS: After PSTA, the mean IOPs from month 1 to month 6 all significantly increased (P<0.05). Ocular hypertension occurred in 30.7% of eyes (median time: 8wk), and severe IOP elevation occurred in 16.2% of eyes (median time: 9wk). Patients receiving PSTA for CRVO or uveitis had a significantly higher risk for ocular hypertension (HR=3.049, P=0.004 for CRVO; HR=5.464, P=0.019 for uveitis) and severe IOP elevation (HR=2.913, P=0.034 for CRVO; HR=7.650, P=0.009 for uveitis). CONCLUSION: IOP significantly increases within 6mo after PSTA, with the onset of ocular hypertension happening mostly at 2 to 3mo. Patients of CRVO or noninfectious uveitis have a higher risk of ocular hypertension or severe IOP elevation after PSTA and should be monitored for IOP more carefully.