Tardigrades are microscopic invertebrates living among mosses and lichens throughout the world. Their occurrence in the states of Kansas and Missouri has only briefly been documented. We report 23 species; 16 species from Missouri and 16 from Kansas. This is the second report of tardigrades from Kansas and only the third from Missouri. This report begins to look at the diversity and distribution of the animals within the two states. Some aspects of the ecology are examined, including the possible relationship between tardigrade species and microhabitats, observations on feeding, and cycles of egg production.