Chemical analysis of suspected Captagon tablets seized between 1986 and 1993 by the drug control authorities in the Kingdom of Saudi Arabia revealed that they often contained different ingredients which would induce effects similar to those of fenethylline. Physical and chemical tests characterised and identified the ingredients which were confirmed by IR, UV and TLC comparison with authentic samples. Apart from fenethylline, caffeine, ephedrine and amphetamine, paracetamol was also detected. It was interesting to note that some tablets contained theophylline, fenfluramine and/or quinine.