The data came from 1,747 juvenile probationers, 565 parolees from juvenile training schools, 800 parolees from prisoners, and 647 offenders who received suspended sentences and were placed on probation. In addition, 586 probation officers from 50 probation officers completed a five- scale evaluation sheet for 72 items relating to treatment difficulty. Results revealed that the number of interviews by probation officers was generally higher for offenders classified as Type A than for offenders classified as Type B. The 10 items with the highest average scores with respect to treatment difficulty included advanced stage of addiction in stimulant drugs, repeated crimes and delinquencies, alcoholic, no way to contact, mentally defective, unable to stop inhaling paint thinner, repeat sex offenders, need to be taken to the probation office by an arrest warrant, and member of an organized criminal group. Factor analysis revealed four general areas related to treatment difficulty. Factors related to probation officers were also related to their concepts of treatment difficulty.