We used Arabidopsis thaliana seedlings as biocatalysts for the reduction of ketones, and investigated the factors affecting the chemical yield and enantioselectivity of the reactions. One- to four-week-old Arabidopsis seedlings were incubated for 24 h in reaction mixture containing either aromatic or aliphatic ketone as a substrate. After the reaction, the ketones and corresponding alcohols were extracted and quantified. The results indicated that Arabidopsis seedlings can be used as a biocatalyst for asymmetric reduction of ketones such as trifluoroacetophenone, t-butyl acetoacetate, methyl benzoylformate, and 2-(trifluoroacetyl)thiophene. The highest chemical yields were observed in seedlings pre-incubated under light conditions and in leaves, suggesting that asymmetric ketone reduction might be related to photosynthesis. In contrast, the age and size of seedlings did not have a significant effect on chemical yield or enantioselectivity. The findings suggest that Arabidopsis, which is widely used as a model plant system, presents a new opportunity for biotransformation.