Data from public and private sectors reveal that few persons stay in psychotherapy long enough to be classified as "long-term" clients. Those who do remain in psychotherapy for a long time are rarely studied because attention has generally been focused on terminators. Demographic, treatment, and psychometric characteristics of 64 long-term clients, i.e., those attending 25 or more sessions, and 88 short-term clients, i.e., those attending fewer than 25 sessions were investigated to determine those variables predictive of long-term stay in psychotherapy. Data were derived entirely from client records. Results indicated there were no differences between long- and short-term clients in terms of age, sex, occupation, IQ, education level, marital status, or presenting problem. The MMPI (Minnesota Multiphasic Personality Inventory) differences suggested that long-term clients were characterized at intake by a more self-critical attitude; less ego strength; greater disturbances in physical functioning; higher anxiety, depression, and confusion; more family disturbances; and greater social isolation. Long-term clients were also more likely to take psychoactive medicine during treatment and to have more insurance coverage than were short-term clients. (Author/HLM)