The authors reviewed four cases of iatrogenic subretinal neovascularization after focal argon green photocoagulation for clinically significant diabetic macular edema. An inappropriate combination of small spot size with a high-power setting is the common feature in each case of iatrogenic subretinal neovascularization. Close follow-up with fluorescein angiography is used to identify iatrogenic subretinal neovascularization at an early, treatable stage. All four patients responded favorably to laser photocoagulation of the subretinal neovascular membrane.