A compression-moulding press for moulding plastic containers (P) consisting of a moulding cavity formed by a plunger (5), a female mould (14), and two separable lips (7, 8). A cylinder (16) slides inside a sliding slide (22) to keep the lips (7, 8) closed. The plunger (5) slides inside the cylinder (16), with respect to both the cylinder (16) and the slide (22), when moulding the containers (P). Finally, a method for making plastic containers by means of compression moulding using said device is also described.