In the pharmaceutical industry, it is common practice to pursue sequentially, within a family of compounds, a number of candidate compounds for further development. This article challenges the sequential tradition, and instead proposes a parallel drug development paradigm, in which several candidate compounds are nominated at the same time, and are simultaneously evaluated through the development process. Evaluating several compounds as candidate drugs (CDs) simultaneously, and in particular in the same studies, will potentially bring huge productivity benefits. The average time to a successful launch, or time to the closure of research on a futile target (family of CDs), may be substantially reduced. Other benefits imply substantially reduced costs as a result of fewer studies, fewer patients receiving placebo, and fewer animals receiving vehicle. A further benefit of the parallel drug development approach is the potential for head-to-head comparison of CDs, leading to improved accuracy in the selection of which compounds to progress through development. A modeling framework has been developed by which development strategies can be compared. Simulations have been performed based on the model. Results are summarized to allow quantitative comparisons of the performance of the parallel development and the traditional sequential development approaches. Drug Dev Res 73: 24–34, 2012. © 2011 Wiley Periodicals, Inc.