The management of organic waste is currently a crucial environmental and societal challenge. Integrating waste treatment with renewable energy production has emerged as promising strategy for reducing the carbon footprint within an energy decarbonization approach. In this context, hydrogen-based biorefineries have gained attention for their ability to convert organic waste into carbon-free energy source. Nevertheless, their large-scale application remains constrained by limited yields, mainly attributed to the synthesis of volatile fatty acids (VFAs) as metabolic by-products. This review focuses on coupling hydrogen (H2) production with polyhydroxyalkanoates (PHAs) production to enhance organic matter recovery and support bioeconomy implementation. A comprehensive description of the coupled process design constitutes the first component of this review, emphasizing the interdependence of feedstock, inoculum types and bioreactor configurations at each stage. Various organic wastes are demonstrated as effective substrates for dark fermentation while the VFAs produced during this stage serve as potential carbon source for PHAs production. The review critically discusses key optimization strategies for the H2/PHAs coupled process, including pretreatment methods application, transition phase management and operational parameters control. It also highlights viable coupling strategies resulting in higher carbon removal efficiency. Based on different life cycle and techno-economic analyses, different challenges in feedstock pretreatment, process efficiency and downstream processing are identified. To overcome these constraints, several perspectives are suggested, emphasizing the relevance of incorporating modelling, nanotechnology and genetic engineering approaches, for better monitoring the coupled process, enhancing its efficiency and thus improving its sustainability and economic feasibility for large-scale implementation.