The caffeine content of selected herbal products and energy drinks available in the Saudi market was determined by HPTLC-UV densitometric analysis. Pre-coated HPTLC silica gel plates (20cm x 10cm) were used for the analysis. The solvent system consisted of ethyl acetate-methanol (85:15, v/v), and caffeine was detected at 275nm. The developed method was validated for specificity, repeatability (C.V. < 5%), recovery (98.90 +/- 3.46), and accuracy (99.84 +/- 2.87). The levels of caffeine were 4.76-13.29% (w/w) and 0.011-0.032% (w/v), for the herbal products and the energy drinks, respectively.