Plant tissue culture is one of the most important tools in modern plant biotechnology. It provides an efficient method for rapid plant propagation, conservation of rare species, production of disease-free plants, and enhancement of valuable secondary metabolites. Medicinal plants contain several bioactive compounds such as alkaloids, flavonoids, terpenes, anthocyanins, and saponins that are widely used in pharmaceutical and cosmetic industries. However, these compounds are generally produced in small quantities under natural conditions. Plant tissue culture techniques, especially hairy root culture induced by Rhizobium rhizogenes, offer a sustainable approach for large-scale production of such metabolites without destroying the mother plant. Important medicinal plants like Vitex negundo and Paederia foetida have shown successful hairy root induction and enhanced metabolite production under in-vitro conditions. These techniques also support germplasm conservation, clonal propagation, and genetic stability assessment through molecular markers. Thus, plant tissue culture acts as the backbone of plant biotechnology by integrating conservation, micropropagation, genetic improvement, and commercial production of medicinally important compounds for pharmaceutical applications.