Pump with plunger pistons comprising a head (1) in which are formed the intake and delivery ducts (2, 3) and the respective intake and delivery valves, a pump body (4) associated with said head (1) in which drive means (8) of at least one piston (6), and attachment and support means (5) of said pump body (4) at a body of the drive motor are situated, where said pump body (4) has, on the bottom wall (40), the seats (41) for the sliding of the pistons (6) and directly carries said attachment and support means (5) of the body of the drive motor and it is completely open on the edge facing towards the motor.