A hand tool with adjustable swing angle includes a first and a second ends connected with each other to contain an adjustable angle. The first end has an upper wall section having a first splined hole and a lower wall section having a through hole. An annular groove is formed on a circumferential wall of the through hole. The second end is formed with a second splined hole positioned between the first splined hole and the through hole. An engagement member having a bulged section is positioned in the splined holes. An elastic restriction ring is positioned in the annular groove and has at least two holding sections positioned in the through hole. When moving the engagement member up and down, the elastic restriction ring is expanded by the bulged section, permitting the engagement member to engage with both the first and second ends or only the second end.