A dimensionless inflow performance relationship (IPR) model, similar to Vogel's method, developed by Chase and Alkandari to predict the deliverability of an hydraulically fractured vertical gas well, has been modified to predict the performance of horizontal gas wells. An equation given in terms of the X e /X f ratio was derived by combining equations offered by Joshi and by Russel and Truitt. Twenty wells were simulated and the IPR curves generated were compared to those obtained using the modified dimensionless IPR model. The average error between the IPR curves generated using the new model and the simulator was 11.1%. When just the absolute open flows were compared, there was an average error of only 3.34%. Reservoir rock and fluid data and modified isochronal test were obtained on a real horizontal well. The IPR curve generated from a conventional modified isochronal analysis and that generated from the new model were compared. The AOFs were within 2.1% of each other, and the average error between the two curves was approximately 4%. The dimensionless IPR curve model appears to offer a cost-effective way of predicting horizontal gas well deliverability.