The Aconoidasida are a class of apicomplexan parasites coined by Mehlhorn et al in 1980.

[1] Organisms in this class bear a tip at one end of their outer membrane.

This apical complex includes vesicles called rhoptries and micronemes, which open at the anterior of the cell.

The tip is surrounded by a band of microtubules, called the polar ring.

As the name indicates, Aconoidasida (from Greek: negative prefix a- = "lacking") lack a conoid (they do have one only during the ookinete stage) in contrast to the class Conoidasida which have one throughout their life cycle.