We provide the first checklist of the obligate aquatic macrophytes of Indiana, including the geographical distribution and frequency of occurrence of each taxon. The checklist is composed of 216 taxa distributed among 85 genera within 43 families. Families exhibiting the greatest richness of taxa are the Potamogetonaceae and Cyperaceae. Approximately 50 % of these taxa are widespread, whereas only 3.7 % are restricted to either the northern or southern regions of the state. An identification code is provided for each taxon and coefficients of conservatism (C values) are given for 189 native taxa, including 18 species of characean algae. C values assigned to native taxa range from 0-10, with a median value of 6. The C values of aquatic macrophytes presented here bear greater similarity to those proposed by Rothrock (2004) for the State of Indiana than to those established by Swink and Wilhelm (1994) for the Chicago region.