This report presents data from the 1991 ARL (Association of Research Libraries) annual salary survey. Forty-two tables report data on professional salaries and years of experience, including a breakdown for minority librarians; distribution of professional staff by salary and position, and by sex and position; the type of institution; and size of professional staff. Tables are organized in five categories: ARL non-university libraries, ARL university libraries, Canadian ARL university libraries, ARL university medical libraries, and ARL university law libraries. An overall summary of the distribution of university librarians and non-university librarians by salary level is also provided, as well as copies of the questionnaires and instructions for the two groups of librarians. (MAB)