Using retired teachers as mentors for beginning teachers in New York City has made real differences in the lives of the new teachers, their mentors, the students, and the supervisors in approximately 100 schools. In these schools more than 100 mentors have worked with 500 teachers over a three-year period. The New York City Mentor/New Teacher Program is described beginning with the introduction of the program to district supervisors and the establishment of agreement on the nature of mentorship. Discussed are recruitment and selection of mentors, mentor training, assignment to and reception of mentors in schools, mentors at work, relationships with teacher supervisors, field supervision, reporting of services provided, and the cost of the program. The program is evaluated in terms of attendance and attrition of new teachers, responses of mentored and non-mentored new teachers, and responses of the mentors. Specific examples from case studies are provided. A table of teacher responses to mentor activities is included, and several forms and workplans used in the program are appended. (MT)