Mass production of value-added molecules (including native and heterologous therapeutic proteins and enzymes) by plant cell culture has been demonstrated as an efficient alternative to classical technologies [i.e. natural harvest and chemical (semi)synthesis]. Numerous proof-of-concept studies have demonstrated the feasibility of scaling up plant cell culture-based processes (most notably to produce paclitaxel) and several commercial processes have been established so far. The choice of a suitable bioreactor design (or modification of an existing commercially available reactor) and the optimization of its internal environment have been proven as powerful tools toward successful mass production of desired molecules. This review highlights recent progress (mostly in the last 5 years) in hardware configuration and optimization of bioreactor culture conditions for suspended plant cells.