Like all Plasmodium species P. diminutivum has both vertebrate and insect hosts.

The vertebrate hosts for this parasite are reptiles.

[1] The parasites have no apparent effect on the host erythrocyte and tend to lie in a polar or lateral position within the host cell.

This species appears to infect only mature cells.

The schizonts are initially round to oval but as they mature become fan shaped with a pigment mass forming the handle of the fan.