Background Human blood is an essential human element for which no substitute has yet been discovered. This study aims to determine the causes of discarding blood and its components. Material and methods A retrospective study of three years (January 1, 2018, to December 31, 2020) was performed in a tertiary care hospital blood bank. Data were retrieved from the various registers and analysed. Results During this study, a total of 3280 units, 1868 units, and 486 units of whole blood were collected in 2018, 2019, and 2020, respectively. It was observed that the discard rate of whole blood was 9.48%, 17.23%, and 43% in 2018, 2019, and 2020, respectively. The discard rate for components varied, such as for packed red blood cells (PRBC), it was 1.76% in 2018, 1.73% in 2019, and 3.03% in 2020, for fresh frozen plasma (FFP), it was 4.08% in 2018, 4.36% in 2019, and 2.20% in 2020, and for platelets, it was 43.08% in 2018, 31.56% in 2019, and 45.03% in 2020. A total of 311, 322, and 209 units of whole blood were discarded in 2018, 2019, and 2020, respectively. The total whole blood and blood components were discarded for various reasons such as undiagnosed sterility (HIV, hepatitis B surface antigen, hepatitis C virus, Venereal Disease Research Laboratory), quality control, underweight, hemolysis unit, expiry, and polycythemia. Conclusion The wastage of stored blood and its components is inevitable. Still, it can be minimised by optimum utilisation and implementation of blood transfusion services (BTS) along with the education and training of blood bank staff. There are various reasons for the wastage of blood and its components, such as unscreened transfusion-transmitted diseases, sterility, storage, less bleeding, expiry, hemolysis samples and polycythemia. Self-regular audits, coordination between hospital and blood bank staff, proper storage and handling of blood units, strict donor selection and deferral criteria, along with appropriate history taking, will help minimise the wastage of blood or its components.