Methyl-, ethyl-, n-propyl- and n-butyl p-hydroxybenzoates (parabens) are used as preservatives in pharmaceutical capsules. In this paper, paraben contents in capsules of commercial pharmaceuticals were examined. Aqueous solution of the sample was extracted with ether, then a portion of the evaporated extract was injected into high-performance liquid chromatograph on a column (30 cm×4.0 mm) of μ-Bondapak C₁₈, with water-methanol mixture (1 : 2, v/v) as mobile phase and finally detected at 254 nm. Also a portion of the evaporated extract was qualitatively analized by gas chromatography on a Silicone GE SE-30 column (1.5 m×3 mm). From 50% of hard capsule samples and 93% of soft capsule samples, parabens were detected. Average and standard deviation of total paraben contents were 0.0761% and 0.0827%, respectively in hard capsules. On the other hand, they were 0.0578% and 0.0601%, respectively in soft capsules. From some of the same pharmaceutical products, various contents of parabens were detected. The practical implications of these investigations were discussed.