Many plants contain valuable compounds which could be used as pharmaceuticals, nutrients, or cosmetics, etc. The objective of the current review is to describe the ENLAC process (enzyme-assisted solid-state lactic acid fermentation) which enables the preservation of plant biomass and enhances the recovery of valuable natural compounds from plants. The advantages attributed to ENLAC include the possibility of preserving the plant biomass until extraction under mild temperature conditions. Using fibrolytic enzymes, it was possible to increase the yield of extracted protein, chlorophyll and β-carotene from alfalfa silages, and to enhance the extraction of polyphenols from ensiled sage and rosemary. A further development of the process included the use of enzymes produced in situ by fungi under aerobic solid-state fermentation, which lowered the estimated costs of ENLAC considerably. We hope that the review will encourage researchers to pursue ENLAC and develop useful applications for it.