Biotechnology methods particularly tissue culture techniques offer new approaches for the in vitro production of valuable plant nutraceuticals. The large-scale production of secondary metabolites in a year-round system without seasonal constraints is one of the advantages of plant tissue culture techniques. Furthermore, enhancement of in vitro nutraceuticals production can be realized by a selection of high-producing cell lines and medium optimization. In this respect, several techniques have been adopted to improve the production of plant-derived nutraceuticals such as mutation, elicitation, precursor feeding, genetic transformation and metabolic engineering. In vitro mutagenesis of cultured cells and tissues by irradiation or chemical mutagens represents a feasible method for the improvement of nutraceuticals production. Likewise, transformation is another strategy that is used to enhance nutraceuticals in plant cells or organ tissues. At this point, hairy root culture induced by Agrobacterium rhizogenes is the most promising transformation technique used for in vitro production of valuable plant compounds. The benefits of hairy roots are high metabolite productivity, high growth rates and inherent genetic stability. On the other hand, due to its effectiveness and practical feasibility, elicitation is considered the most applied strategy for enhancing the production of desired compounds in plant biotechnology. Biotic (biological origin) and abiotic (non-biological origin) elicitors are used to increase the production of plant metabolites by different effects on the cellular processes in the plant system. Furthermore, bioreactors developed for in vitro industrial-scale production of desired compounds can be used for continuous and scaling-up plant nutraceuticals production. This article discusses different aspects of biotechnology used for the selection and enhancement production of nutraceuticals from plant cultures grown cells, in vitro.