Experimental service protocols tailored to the needs of teenage family planning patients were developed that emphasized indepth counseling, education geared to an adolescent's level of development, and the provision of reassurance and social support. These protocols were tested against usual service delivery practices in a study involving 1,261 patients under 18 years of age at six nonmetropolitan family planning clinics. A comparison with teenagers obtaining services at control sites found that six months after their first clinic visit, patients at the experimental sites were more likely to be using a method, were less likely to experience difficulty in dealing with problems, were more likely to continue using their method despite problems and had learned more during the educational session. Teenage patients at the experimental clinics were also less likely to have become pregnant within one year than those who went to control clinics. Attrition during the year following the first study visit was similar among both groups; patient satisfaction was very high, and equivalent at experimental and control sites. The data show that the extra time and effort required to meet the special needs of teenagers is justified by their improved contraceptive use, greater knowledge and lower pregnancy rates.