Abstract: A two part medical infusion pump comprises a first portion incorporating a pump mechanism, a pump control system, and a tube support, and further comprising a second portion arranged for detachable mounting to the first portion. The second portion carries a fluid-containing cassette and an associated fluid delivery tube. The tube support is arranged to be automatically moved out of a path of the fluid delivery tube as the first and second portions are moved towards an engagement position. The pump mechanism is arranged to compress the fluid delivery tube against the tube support of the first portion when the second portion is in the engagement position, such that controlled delivery of the fluid in the cassette to a patient is affected.