The hypothesis that Haliotrema species from boxfishes form a monophyletic lineage was tested. The analysis was conducted for an ingroup of 62 species (including 10 from boxfishes), in a matrix of 20 terminal taxa and 17 characters (total of 21 states). Eight equally parsimonious cladograms (c.i. = 84%, r.i. = 91%) were generated. Two Haliotrema species from boxfishes (H. lactoriae and H. triacanthi) were found to be more closely related to other Haliotrema species than to the remaining 8 from boxfishes. The remaining 8 (H. trochaderoi, H. crymanum, H. lactophrys, H. guadeloupensis, H. glandulosum, H. torridum, H. minutum, and H. kritskyi) constituted part of the bodiani group (total of 19 species). Five of the 17 characters from the analysis were hypothesized to contain homoplastic states. Missing character coding, rounding error, and "ghost characters" influenced resolution.