We report several cases in which Gordionus lineatus (Horsehair Worm) (Nematomorpha) parasitizes the diplopod Cambala annulata (Myriapoda, Diplopoda) in Ohio. Diplopods as host for nematomorphs in North America have previously only briefly been mentioned. This report is the first host record for a Nearctic Gordionus species. Gordionus lineatus is also a new record for Ohio. Though the sample size is small, the prevalence may be high (50%). Myriapods appear to survive the parasitization. As Cambala annulata is likely to be herbivorous, pathways of infection with nematomorphs are discussed.