Abstract: A tire pump with a pressure gage including a cylinder having a piston rod and a piston head slidably provided in the cylinder. A peep hole is formed in the cylinder. An outlet is formed at a front end of the cylinder. A pressure measuring device with a pressure indicating element is disposed at a front end of the cylinder so that the pressure indicating element is readable through the peep hole. The pressure measuring device interconnects the outlet of the cylinder. A bypass tube with a check valve is disposed beside the pressure measuring device so that air pressurized by the piston head flows out from the outlet through the bypass tube. The pressurized air also flows through air holes in order that the pressure within the pumped tire can be read from the pressure indicating element of the pressure measuring device through the peep hole.