ABSTRACT Plasmodium parasites rely on a functional electron transport chain (ETC) within their mitochondrion for proliferation, and compounds targeting mitochondrial functions are validated antimalarials. Here, we localize Plasmodium falciparum patatin-like phospholipase 2 ( Pf PNPLA2, PF3D7_1358000) to the mitochondrion and reveal that disruption of the Pf PNPLA2 gene impairs asexual replication. Pf PNPLA2-null parasites are hypersensitive to proguanil and inhibitors of the mitochondrial ETC, including atovaquone. In addition, Pf PNPLA2-deficient parasites show reduced mitochondrial respiration and reduced mitochondrial membrane potential, indicating that disruption of Pf PNPLA2 leads to a defect in the parasite ETC. Lipidomic analysis of the mitochondrial phospholipid cardiolipin (CL) reveals that loss of Pf PNPLA2 is associated with a moderate shift toward shorter-chained and more saturated CL species, implying a contribution of Pf PNPLA2 to CL remodeling. Pf PNPLA2-deficient parasites display profound defects in gametocytogenesis, underlining the importance of a functional mitochondrial ETC during both the asexual and sexual development of the parasite. IMPORTANCE For their proliferation within red blood cells, malaria parasites depend on a functional electron transport chain (ETC) within their mitochondrion, which is the target of several antimalarial drugs. Here, we have used gene disruption to identify a patatin-like phospholipase, Pf PNPLA2, as important for parasite replication and mitochondrial function in Plasmodium falciparum . Parasites lacking Pf PNPLA2 show defects in their ETC and become hypersensitive to mitochondrion-targeting drugs. Furthermore, Pf PNPLA2-deficient parasites show differences in the composition of their cardiolipins, a unique class of phospholipids with key roles in mitochondrial functions. Finally, we demonstrate that parasites devoid of Pf PNPLA2 have a defect in gametocyte maturation, underlining the importance of a functional ETC for parasite transmission to the mosquito vector.