Joslin was the first physician in the United States to specialize in the treatment of diabetes; this was the first textbook on the subject in the English language. The book underwent its 12th edition in 1985. Digital facsimile of the first edition from the Hathi Trust at this link.

Joslin founded the Joslin Diabetes Center, "the world’s largest diabetes research center, diabetes clinic, and provider of diabetes education. It is located in the Longwood Medical and Academic Area in Boston, Massachusetts."