Biochar – also referred to as biocarbon, agrichar – shows similar properties as charcoal but indicates applications for agriculture and environment protection. Biochar was applied in the 19th century agriculture practices in Europe and South America. At present, the properties of biochar are being „redescovered” and new areas of applications include production of bioenergy, waste management or mitigation of climate change. Also, it can be used for sequestration of carbon in soils, remediation of soil contaminated with organic and inorganic compounds. Biochar can be produced through pyrolysis of a wide range of feedstock materials including energy crops, forestry residues, agricultural biomass, sewage sludge, food processing waste, etc. Depending on the initial properties of substrates and parameters of pyrolysis biochars can demonstrate various properties such as high content of stable organic carbon and minerals, high porosity and surface area, and thus increased sorption and nutrient retention properties. Recent studies show that biochar can be also used in composting and production of biochar-based composts and fertilizers. Biochar can function as a bulking agent or an amandment for composting of materials with high moisture and/or nitrogen contents. The addition of biochar to composting mixtures can reduce ammonia emissions, and thus limit nitrogen losses during composting, increase water holding capacity and retention of nutrients. Biochar can also function as a carrier substrate for microbial inoculants and a scrubing material used in biofilters at composting facilities. Due to the fact that the literature does not provide many examples of biochar applications for composting, and there is little known about the effects of biochar added to composting mixtures on composting dynamics and properties of final composts, futher investigations should focus on mechanisms of biochar-composting mixtures interactions and analysis of properties of biochar-based composts. The overall goal of the article is to analyze the potentials of biochars for composting, to report the effects of various biochars on composting dynamics and quality of produced biochar-based composts, and to indicate the areas of further studies on biochar properties that would allow optimization of composting and improve the quality of final products.