Evaluation of recall and performance skills required to clean needles/ syringes was conducted in Dade County with 393 injecting drugs users (IDUs) in 1988-1989. The study was guided by a question of the extent of correct cleaning of needles/syringes. A free recall procedure which combined cognitive and psychomotor testing provided a means of verifying knowledge and skills. The results show that injecting drug users were able to learn and retain knowledge and skills necessary to prevent risk of HIV infection by use of needles/syringes. Tests of knowledge and performance 6 months after training showed high retention of the material learned. The population at risk is capable of reducing the spread of HIV. The impact would be greater with perfect performance, but even with partial performance, some preventative impact could be assumed provided exposure time to bleach exceeds 30 seconds.