THE GUIDELINES WERE DEVEOPED IN THERAPY SESSIONS WITH 150 SEVERELY DELINQUENT GIRLS OVER A PERIOD OF 7 YEARS IN A LOS ANGELES COUNTY PROBATION DEPARTMENT SCHOOL (CALIFORNIA). THE GIRLS, AGES 13 TO 17, HAD BEEN TO COURT AT LEAST ONCE AND HAD ALREADY FAILED IN A WIDE VARIETY OF TREATMENT MODALITIES. THE TIME AND THE MODE OF INVOLVING THE FAMILIES IN THERAPY IS CAREFULLY CONTROLLED BY THE SCHOOL AND CAN BE DIVIDED INTO SIX PHASES: (1) SEPARATE INTERVIEWS FOR THE DELINQUENT AND FAMILY, (2) THE ESTABLISHMENT OF THERAPEUTIC RELATIONSHIPS BETWEEN THE THERAPIST AND EACH FAMILY MEMBER, (3) FAMILY INTERVIEWS AND ELECTIVE FAMILY THERAPY WITH THE DELINQUENT, (4) UNSUPERVISED VISITING BETWEEN THE FAMILY AND THE DELINQUENT AT SCHOOL, (5) A HOME VISIT BY THE THERAPIST WITH THE FAMILY AND THE DELINQUENT, AND (6) HOME VISITS BY THE DELINQUENT WITHOUT A THERAPIST. THE TIME OF INVOLVEMENT DEPENDS NOT ONLY ON THE PATIENT BUT UPON THE FAMILY ATTITUDES WHICH MAY BE CONVENIENTLY DIVIDED INTO THOSE WHO COLLUDE IN THE GIRL'S DELINQUENCY, THOSE WHO OPPOSE THE DELINQUENT BEHAVIOR BUT CANNOT TOLERATE EMOTIONAL DEMANDS FROM THE DAUGHTER, AND THOSE WHO DO NOT TRY TO RESTRICT THEIR DAUGHTER'S BEHAVIOR BECAUSE THEY ARE SYMBIOTICALLY BOUND TO HER OR HAVE GIVEN UP STRUGGLING TO CONTROL HER DELINQUENCY. FOR FAMILIES WITH SEVERELY DELINQUENT DAUGHTERS, ENFORCED SEPARATION FOLLOWED BY A GRADUAL REUNITING OF THE FAMILIES REPRESENTS THE MOST EFFECTIVE TREATMENT. HOWEVER, IF IT BECOMES CLEAR THAT THE GIRL CANNOT BE RETURNED TO HER FAMILY, FAMILY THERAPY WILL BE UNDERTAKEN AT ALL. CASE HISTORIES ILLUSTRATE THE BEST APPROACH FOR EACH TYPE OF FAMILY, AND THE NEED FOR FLEXIBILITY IS EMPHASISED. SEVERAL REFERENCES ARE PROVIDED. (SAJ)