There is a close relationship between interannual variability of the Indian summer monsoon rainfall and the El Nino/Southern Oscillation (ENSO) (drought conditions over India accompany warm ENSO events and vice versa). However, recent observations suggest a weakening of this ENSO-monsoon relationship that may be linked to global warming. We report here an analysis of the ENSO-monsoon relationship within the framework of a 1000-year control simulation of the MRI-coupled general circulation model (GCM), MRI-CGCM2.2. An overall correlation between the June-July-August (JJA) Nino3.4 sea surface temperature and the JJA Indian monsoon rainfall is –0.39, with reasonable circulation characteristics associated with the modeled ENSO. The simulated ENSO-monsoon relationship reveals long-term variations, from –0.71 to +0.07, in moving 31-year windows. This modulation in the ENSO-monsoon relationship is associated with decadal variability of the climate system.