Eosinophils are most easily recognized by their characteristic large reddish-orange granules. They typically have a bilobed nucleus with dark purple clumpy chromatin.

Neutrophils with toxic granulation can be confused for eosinophils, especially if the staining is poor. However, the toxic granules in neutrophils are dark blue instead of a reddish-orange color. The granules in neutrophils are also not as large.