A Post Keynesian macromodel of capacity utilization and economic growth is developed in which the supply of credit-money by the banking system is endogenous, and firms' financial fragility is explicitly modeled. Both the influence of interest rate and indebtedness on capacity utilization and the rates of profit and economic growth, on the one hand, and the effect of the parameters of the saving and investment functions on firms' financial fragility, on the other hand, are carefully analyzed.29193115