Polyhydroxyalkanoates (PHAs) are steadily getting integrated into our daily life due to their biocompatibility, biodegradability, and production from renewable sources. Different microbial species can accumulate the PHAs from verities of substrates and yield can be improved by strategic optimization of carbon flux into the biomass growth and polymer accumulation. Modelling bioprocess of PHA production is not only essential to understand the dynamics but also to trace the optimal operating conditions. A variety of models has been proposed in the literature depending on single or multi-substrate growth, involvement of substrate or product inhibition and parametric perturbation shifting from growth to PHA accumulation phase. Therefore, this communication attempts to review the scientific basis, assumption, usage, and limitations of those mathematical models at large while suggesting improvement on existing ones. Exploration of those models in different bioreactor systems, adopted strategies in model selection exercise has also been reviewed.