The study investigated the effect of monetary policy instruments and macroeconomic policies on institutional microcredit supply to the agricultural sector in Nigeria. The track record of agricultural credit delivery in Nigeria has been un-encouraging and assessment studies on the subject have focused mainly on the informal and public sector initiatives with scant attention on private sector, institutional microcredit. This gap is what this work attempts to fill. First, the study explains the concept of institutional microcredit and how it differs from other forms of credit. In so doing, it aims at removing the fog around the subject of microcredit and other forms of credit generally, so that policy articulation will become more precise and implementation, more focused. The study also aims at determining the growth of institutional microcredit supply to farmers and its response to the major policy initiatives of government over the years. The work thereby provides a platform for self appraisal for Nigerian policy makers and serves as a veritable tool for policy redirection, realignment and emphasis. It is also a good reference material for further research on the subject.