A protocol is presented for the purification of sporozoites from sporulated oocysts of Eimeria tenella. Two Percoll density gradients are the basis of the purification. The first gradient is used after glass-bead grinding to purify undamaged sporocysts; 87% of the sporocysts loaded onto the gradient were recovered in the pellet. The second gradient is used after excystation to purify sporozoites; 98% of the sporozoites loaded onto the gradient were recovered in the pellet. The sporozoites are 99% pure with a final recovery of about three sporozoites per oocyst.