Subprime mortgage crisis is defined as a nationwide banking emergency that coincided with the U.S. recession of December 2007 – June 2009. This incident had been analyzed from various aspects as it redefined the world economy and the largest banking and financial institutions of the world. A major American financial services company Citigroup suffered the crisis caused by manifold contributing reasons that could be triggered and prevented prior to the crisis, is analyzed here. Secondary data had been used here to formulate the thorough study from sources like Reuters, Sonntag, Barnett-Hart. Excessive issuance of CDOs by Citigroup to reallocate risk, regulate capital relief and earn greater profit was the substantial reason of its distress. Besides insufficient risk management resulting from risk managers’ cronyism and retransfer of huge amount of troubled assets back into its balance sheet to avoid the forego of its institutional clients due to shadow banking added to the situation. The crisis resulted in a numerical loss of $18.72 billion and around 100000 job cuts during 2008 period. Government aid like bail-out and internal restructure was implemented by this giant institution to overcome the distress. An analysis, backed by the study of the overall mishap suggests that, providing Citigroup with independent risk management, credit rating of its internal departments with stricter regulations, audits and checking rather than profit oriented private rating agencies and deeper focus on future strategies would act better as measures to prevent recurrence of such crisis and to eradicate the impact of the happened crisis in Citigroup. Until the subprime crisis in 2008, Citigroup used to be the largest bank in the world by total assets which motivated us to choose Citigroup to focus on this report (stempel & wilchins, 2007). The extent of damage to which Citigroup