Using light and scanning electron microscopy, the internal male and female reproductive anatomy of the praying mantid Ciulfina klassi is identified and described. This is the first detailed study to investigate the internal reproductive morphology of any Mantodea. The female structures identified were (1) paired ovaries with primitive panoistic type ovarioles, (2) a single blind-ended spermatheca with secretory gland cells and surrounding layer of striated muscle, and (3) female accessory glands associated with the production of the ootheca (the egg casing). The male structures identified were (1) paired multi-tubular testes, in which different stages of spermatogenesis were observed, (2) tubular vasa deferentia, (3) seminal vesicles, (4) male accessory glands and (5) a single muscular ejaculatory duct. Knowledge of basic reproductive morphology can be used to infer function and so provide key information for future research into reproductive behavior and physiology in the Mantodea.