The bryoflora of Martha’s Vineyard and Nomans Land has received little organized study. However, these islands of 100 mi2 and 1 mi2, respectively, seven miles south of Cape Cod, are of considerable bryological interest. They are part of the Atlantic Coastal Plain and are located near the northern, largely submerged end of this physiographic province, which extends southward along the entire eastern coast of the United States. Late Pleistocene glaciers reached as far south as the Vineyard area, leaving behind massive deposits of terminal moraine and associated outwash that remained above sea level as islands when the sea transgressed landward at end of the Ice Age. The maritime climate of Martha’s Vineyard and Nomans Land is characterized by moderate temperatures throughout the year, and the islands lack large seasonal temperature variation typical of more continental regions. Thus, on the basis of these and other circumstances the bryoflora of the Vineyard and Nomans Land was expected to consist of an interesting mixture of southern and northern species, some of which potentially are at their range limits. Four visits to Martha’s Vineyard and one visit to Nomans Land resulted in 480 collections documenting 168 taxa (1 hornwort, 43 liverworts, and 124 mosses). Of these, 15 (11 1iverworts, and four mosses) are new records for Massachusetts. A list of the taxa found and brief descriptions of collecting sites are presented in two appendices.