The construction industry, a major contributor to global CO2 emissions, has explored innovative solutions to reduce its carbon footprint. A promising avenue is the integration of biochar, a porous carbonaceous material derived from biomass, into cement-based materials. Biochar, a porous carbonaceous material derived from thermochemical conversion of biomass has emerged as a technology for carbon dioxide (CO2) capture and sequestration and has gained prominence as a crucial alternative in combating climate change, recognized by the IPCC since 2018. Biochar’s effectiveness in carbon dioxide (CO2) capture stems from a combination of physical adsorption and chemisorption processes, which are enhanced by optimizing its pore structure, surface chemistry, and mineral content. When incorporated into cement-based materials, biochar acts as a partial replacement for cement or aggregates, offering benefits such as increased mechanical strength, enhanced durability, and improved hydration. Carbonic curing, mineralization or enforced carbonation are expressions being used when CO2 reacts with Portland cement materials at an early age to convert Ca(OH)2 into stable CaCO3, boosting the material’s final strength and durability. Biochar’s inherent properties, such as its high porosity and specific surface area, make it an excellent internal curing agent and facilitate CO2 diffusion within the matrix. The aim of this article is to present, based on some articles published from the last 5 years, a compilation of key factors that influence the CO2 uptake of cement-based materials at early ages with biochar. Some of these factors are the biomass source, pyrolysis temperature, particle size and humidity control (internal and external). While biochar can function as a “filler” or exhibit pozzolanic activity, its interaction with cement and other supplementary cementitious materials (SCMs) require consideration, as high dosages can reduce overall CO2 capture capacity. Furthermore, chemical and physical modifications can increase the capacity of biochar’s CO2 adsorption in cement-based applications.