In this work a novel Monte Carlo method is developed to simulate the equilibrium thermodynamic properties of strongly associating fluids. The highly anisotropic nature of intermolecular interactions in these fluids makes conventional simulation techniques of little use. By introducing biased sampling techniques we are able to explore configuration space efficiently, thereby obtaining reliable estimates for the thermodynamic properties, including phase equilibria, of model systems. The results of our simulations are used to assess the accuracy and validity of various theories for associating fluids.