Why does my car keep overheating after I put in new thermostat

It could be something as simple as the hose is bad that carries water and or coolant to the motor. It could be a leak in the housing of your coolant. it could even be the water pump that went out and that is why your car is over heating. That had happened to me, the seal on the water pump had gone bad so it would leak coolant every now and again and i had to keep putting water in the tank so it doesn't over heat. Point i am trying to make is that it probably was not the thermostat that is making the car over heat but some other component like water pump or hoses.

AAcertified said it all,have your coolant system pressure checked for leak,s,if you find it fix it,if not you have a bad water pump or coolant fan issue.

did you put the thermostat in backwards? air in the system/not properly bleed? if the overheating problem did not occur until you touched it, then its most likely something you did/or did not do...