(R)-(+)-Limonene is an optically active (R) form of limonene. Limonene is a 10-carbon cyclohexanoid monoterpene. It is widely employed in cosmetic industry. (R)-(+)-Limonene is present in the peel oil from citrus fruits. It is the most commonly used fragrance materials in technical products and in fine fragrances. It is the major constituent of the essential oil extracted from Anethum sowa Roxb. (Indian dill). Racemic limonene undergoes enantio-selective and enantio-specific conversion to (R)-(+)-α-terpineol byPenicillium digitatum mycelia. Biotransformation of (R)-(+)- and (S)-(-)-limonene by fungi has been investigated.