Purpose. To evaluate the effect of a fluorometholone/tetrahydrozoline fixed combination on conjunctival graft morphology after primary pterygium excision. Methods. The patients who underwent pterygium excision with conjunctival autograft transplantation were randomized into three groups based on postoperative medications as the fluorometholone/tetrahydrozoline group, fluorometholone group, and dexamethasone group. Conjunctival graft thickness was measured with anterior segment optical coherence tomography. The conjunctival graft hyperemia was evaluated using a high definition external camera. Results. The mean graft thickness was significantly lower in the fluorometholone/tetrahydrozoline group compared with fluorometholone and dexamethasone groups at 2 weeks (P = 0.002 and P = 0.012, resp.) and at 1 month after surgery (P = 0.003 and P = 0.013, resp.). The conjunctival hyperemia score was significantly lower in the fluorometholone/tetrahydrozoline group compared with fluorometholone and dexamethasone groups at 2 weeks (P = 0.000 and P = 0.000, resp.) and at 1 month (P = 0.039 and P = 0.040, resp.). The graft thickness and conjunctival hyperemia score were similar among the groups at 1 week and 3 months (P > 0.05). Conclusion. The findings of the present study revealed that treatment with the fluorometholone/tetrahydrozoline fixed combination may be helpful to decrease graft edema and to achieve better cosmetic appearance at 2 weeks and 1 month after pterygium excision.