The large waqf complex of Süleymaniye in Istanbul held vast agricultural lands and numerous revenue-yielding real estates. However, in 1586, it was mentioned as being in debt to butcher and grocer in an official document. The financial distress of the waqf around the 1580s could have not been determined although the waqf has been examined through its account books. The present study using the detailed registers shows that the waqf experienced serious difficulties in revenue collection. This study particularly emphasizes two points. First, the detailed registers are valuable sources supporting the financial analysis of the waqf institutions. Secondly, considering the fact that the Süleymaniye was deriving the major part of its income from the rural areas in the Balkans, the financial hardship of the waqf may imply deterioration in agricultural conditions. Therefore, future research analyzing the waqf for a longer term is significant to reveal economic conditions in the Balkans.