Examination of coelomic cavities of 22,508 chaetognaths revealed the presence of 19 hemiurid metacercariae representing 3 genera as follows: Brachyphallus sp. from Serratosagitta serratodentata, Ectenurus sp. from Parasagitta friderici, and Lecithochirium sp. from Flaccisagitta enflata, S. serratodentata, Sagitta bipunctata, and Sagitta helenae. Samples were collected along the Mexican coast of the Caribbean Sea from 50 m depth to surface during February, March, May, and August 1991. Overall prevalence and mean infection intensity were 0.084% and 1.0, respectively. Serratosagitta serratodentata and S. helenae represent new host records for hemiurids.