Modafinil is a novel wake promoting agent approved in Australia for the treatment of narcolepsy. Preliminary studies have suggested that modafinil may have value in the treatment of psychostimulant dependence through positive effects on mood, sleep patterns, concentration, fatigue and drug craving. It appears to be well tolerated with a low abuse potential. Sixty dependent methamphetamine users will be allocated to 2 equal groups. The experimental group will receive modafinil 200 mg/day for 10 weeks and a tailored cognitive behavioural therapy program. The control group will receive placebo under equivalent conditions. Primary outcome will be a between group comparison of methamphetamine negative urine samples over the 10 week study period. Adverse events, side effects, compliance, retention and self reported health, psychosocial and drug use will also be compared between the study groups.