Plasmodium is minute, slender and sickle shaped in appearance. Its body is pointed at both the ends and is slightly curved towards one side.
In sporozoite stage, it is about 14 u in length and 1 u in width. Its body remains covered externally by a thin, firm, elastic and non-resistant cuticle, which helps in maintaining a definite shape. The middle part of the body is slightly thicker due to the presence of nucleus.
Apart form this plasmodium is a single celled parasite having apical cap at the anterior end. Microtubules are present in the pellicle. Paired organelles, tubules, micropyle, mitochondria with some other cellular organelles are also present in the cellular body plasmodium.