The advantage of utilizing modeling to study fire performance of textiles is the ability to conduct detailed studies of the effect of fabric characteristics on flame spread. First, two textile materials are chosen for modeling that exhibit two limit cases: complete flame spread (nylon 6,6/cotton fiber fabric) and self-extinguish (flame retardant rayon/nylon 6,6/para-aramid fiber fabric) in the standard vertical flame test (ASTM D6413). Parameter estimation for unknown model parameters is performed for these samples followed by a sensitivity analysis. Then a new sample is modeled—flame retardant cotton fiber fabric, flame retardant cotton. This modeling exercise shows that computational fluid dynamics modeling is capable of capturing the fire characteristics of different fabric samples in the vertical flame test only when the parameters are carefully estimated considering the modeling assumptions and approaches. Additionally, several areas for further investigation are proposed to improve simulation capability when conducting vertical flame test modeling with textile samples.