Samples of two parasites were collected throughout their complex life cycles, the nematode Camallanus lacustris and the cestode Schistocephalus solidus. RNA was extracted from 7 life stages of C. lacustris and 10 life stages of S. solidus, with 3-7 replicates per stage, before being sequenced on an Illumina Novaseq 6000. Our motivation was quantifying changes in gene expression as parasites infect and exploit dissimilar hosts during their life cycles.