Abstract: An automatic injection device for providing a subcutaneous injection is disclosed. The device includes a syringe movably disposed in a housing and including a barrel portion, a needle and a bung for sealing the barrel portion. The device includes a plunger for moving the syringe towards a first open end of the housing such that the needle projects from the first end, and for subsequently applying pressure to the bung. The plunger includes a rod connected at a first end to the bung, a compressible expanded central portion, and a flange between a second end of the rod and the central portion. The device also includes a biasing mechanism for biasing the plunger towards the first open end of the housing, the biasing mechanism disposed about the second end of the rod between the flange and a second end of the housing.