Background: Safe transfusion focuses on reducing patient the risks of blood transfusion reactions due to incompatible blood and blood products. The clerical errors and ABO discrepancies are serious health obstacle those faced the possess of blood transfusion. Method: This cross sectional study was conducted in different blood banks in the Khartoum State to detect the clerical errors and ABO discrepancies in 1200 collected donors blood bags. Manual direct serologically ABO grouping method analyzed those bags. Results: The obtained analyzed results reported total summation of clerical errors and discrepancy in all blood banks in the Khartoum State was 3.5% (42/1200) and 0.58 %( 7/1200) respectively. The frequencies of clerical errors were distributed as; 1% (12/1200) for technical, 0.75% (9/1200) for adhesive sticker and 1.75% (21/1200) for document registration in files and for the discrepancies as; A2 0.08% (1/1200), A2B 0.25% (3/1200), auto AB 0.17% (2/1200), and B-acquired 0.08% (1/1200). Conclusion: The highest number of clerical errors and discrepancies were observed so, it is very important to find out the discrepant results and resolve them. Therefore, the precision of performing the ABO blood grouping and well identification of donors are essential to prevent the incompatibility of ABO grouping.