Plasmodium is a genus of unicellular eukaryotes that are obligate parasites of vertebrates and insects. The life cycles of Plasmodium species involve development in a blood-feeding insect host which then injects parasites into a vertebrate host during a blood meal. Parasites grow within a vertebrate body tissue before entering the bloodstream to infect red blood cells. The ensuing destruction of host red blood cells can result in malaria. During this infection, some parasites are picked up by a blood-feeding insect, continuing the life cycle.

प्लास्मोडियम एक प्रोटोज़ोआ संघ का प्राणी है। प्लास्मोडियम की कुछ जातियों को मलेरिया परजीवी भी कहते हैं क्योंकि ये मनुष्य मे मलेरिया रोग उत्पन्न करती हैं।