Supply chain management aims to enable an efficient flow of right products to the right places at the right time so as to create value to the customers while making sure to minimize costs for the company. Fast fashion means reduced time between the design and the delivery process. New styles reach the stores faster from the designers table. But, brands in fast fashion retail network like Zara, H&M and Topshop often face challenges which include short product life cycle, reduction in lead times for retail inventory, distribution of products within fourteen to fifteen days after they first appear on the fashion shows and also the issue centered with the incentives of the sales managers. This research paper focuses on how these major fast fashion brands mainly Zara and H&M overcome the major challenges by adopting inventory management strategy. Fashion is just not all about dressing up and supply chain management of H&M and Zara is a proof to that which is globally recognized as a successful and extensive retail giant. H&M ranks number three on Gartner’s Supply chain. And it also provides a comparative analysis of their inventory management techniques.