Microalgae have the potential to be an excellent source of sustainable and renewable biofuel. However, different issues surrounding their economic viability and upscale application need to be resolved. Microalgal dewatering requires substantial energy to concentrate the highly dilute microalgal culture and is considered a major bottleneck that limits industrial mass production. Compared to conventional planktonic microalgae growth systems, the attached growth or biofilm-based growth represents several advantages such as higher biomass content compared to liquid culture and lower capital costs, which has a great potential to help microalgal fuels reach economic viability. However, despite the many advantages of biofilm-based growth, limited work has been reported on their use to mass produce microalgal biofuels or bioproducts. Houda’s work focuses on the current challenges in microalgal biofilm development and identifies strategies to improve biofilms growth, to optimise the economics of microalgal biomass production and downstream processing, and to promote the commercial industrialisation of algal biofilm.