Professor Badr El Din A. Ibrahim, President of the Microfinance Unit at the Central Bank of Sudan, discusses ways to implement Shari'ah-compliant microfinance. There are some options to introduce it in the existing conventional microfinance institutions (MFIs). Hence, separate windows for conventional MFIs, not banks, are necessary to extend interest-free finance. Challenges for the Islamic windows-based business model are Shari'ah compliance and the need for changing regulatory requirements to allow for this model. The choice of Islamic windows requires raising new capital exclusively for the window.