We label 1000 Romanowsky-stained thick blood smear images previously used in actual diagnoses. This dataset has 1.000 Romanowsky-stained thick blood smear images from the INS (National Institute of Health in Colombia). The photographic records came from 100 thick blood smears (10 images of different fields per slide). There were 217 and 783 images of good quality and bad quality, respectively. Of these, 702 images were with the presence of parasites and 298 without parasites. A total of 6188 parasites (Trophozoites - 5927, Squizonts - 114, Gametocytes - 147) were labeled, whose height and width varied from 13 to 138 pixels. Each image with parasites included from one to ninety parasites, with an average of eight per image. In addition, there were 12.712 leukocytes in all the images, whose height and width varied from 15 to 222 pixels, and only in twelve of the images were no leukocytes found.