Background Crabs are one of the most diverse groups of crustaceans. Both fresh and marine crabs are an excellent source of many nutrients that are important for human health. Because of their unique flavour and delicious taste, crab meat and novel crab-based processed products are quite popular; hence the demand is increasing consistently in the domestic and global market. Further, crab processing generates a large quantity of liquid and solid waste creating disposal and land fill problems. To overcome the environmental impacts thereof, it is necessary to recycle and reuse these underutilized yet economically potential discards or by-products. Scope and approach Even though having immense potential in terms of nutrients and offering unique flavour profile, the importance of crab often goes unnoticed. But crabs get less special mention and are mostly considered along with other crustaceans, wherein shrimps and lobsters are debated at length. Further, crab processing generates a large quantity of by-products and solid wastes, predominantly rich in chitin. Therefore, there is a great interest for valorisation of crab processing by-products that possess biologically active products with wide applications. In light of the above, this review highlights the nutritional aspects, flavour profile, quality and health benefits of crab meat including the acceptability of crab-based value-added products. The diversified applications of valuable products derived from crab processing bio-wastes are also discussed. Key findings and conclusions Crab meat is rich in protein, essential amino acids, long chain omega-3 fatty acids, and also an excellent source of vitamins and minerals. The uniqueness in taste and pleasant flavour properties of crab meat is due to volatile, non-volatile aroma and taste components, hence highly accepted by the consumers. Different innovative preservation technologies are suggested to improve the quality, safety and shelf-life of crab meat and crab-based value-added products. Further, crab processing wastes possess several high-value bioactive compounds. Green extraction is recommended for valorisation of these bioactive compounds (derivatives of chitin, protein hydrolysates and enzymes, lipids, carotenoids etc.) that have enormous applications in agriculture, environment, food, textile, pharmaceutical and other biomedical fields.