The Systems Improved Numerical Differencing Analyzer and Fluid Integrator (SINDA/FLUINT) program is a thermal analyzer code which has frequently been used as a design and analysis tool, to determine the transient and steady-state response of various fluid flow and thermal networks. While this code has provided important information in the design and analysis of a variety of aerospace systems, the validation of the code has been limited to a few simple test cases, and did not examine the resistance-capacitance or fluid flow network solving capability of the code.For the current study, the predictions from several simple models were compared to their corresponding analytical solutions. The first comparison considered steady-state, one-dimensional heat conduction in a constant area fin with four different fin tip boundary conditions. The second portion of the study examined an infinitely long fin which rejects heat to the environment by a simultaneous convection and radiation process. The next segment of the study compared the predicted cooling of a cube with the results produced by the Heisler chart method. Two fluid flow situations were also considered. The first case examined the flow in a circular duct which connects two infinitely large pressure reservoirs. The second fluid flow case examined the filling of a tank which experiences both heat transfer and control volume work. The results of all these comparison studies showed that the code was able to predict temperatures within 0.5% of the analytical solutions.