Immobilized plant cell cultures ofCapsicum frutescensMill. were treated with the ferulic acid and vanillylamine in order to study their biotransformation ability. It was found that ferulic acid and vanillylamine were biotransformed to capsaicin and vanillin. Ferulic acid treated cultures produced more vanillin than capsaicin whereas vanillylamine treated cultures produced more capsaicin. This trend was expected since ferulic acid and vanillylamine are the nearest precursors to vanillin and capsaicin, respectively. Maximum vanillin (315μg/culture was observed in ferulic acid (2.5 mM)) treated cultures on the 15th day and maximum capsaicin (190 μg/culture) was in vanillylamine (2.5mM) treated cultures on the 6th day. It was shown that immobilized cell cultures ofC. frutescenscan perform oxidative deamination, a reversible reaction which was evident by conversion of vanillylamine to vanillin. This study also provides an example for an alternative route to formation of vanillin by cell culture