The impacts of nucleate boiling and pressure on crude oil fouling are factors that have not been heavily investigated in previous research. Variables such as wall temperature and fluid velocity/shear are often a main focus, as they are key variables for predictive fouling models, which provide insight to fouling thresholds. Research detailed in this report shows that nucleate boiling and pressure greatly impact the measured fouling rate of a crude oil tested using the Heat Transfer Research, Inc., rotating fouling unit. When nucleate boiling is occurring, the use of fouling resistance plots to measure fouling rates is not a reliable method due to the impact boiling has on the heat transfer coefficient. Visual inspection of fouling deposits to validate fouling resistance data has also been found to be critical. Images of fouling deposits are included. Fouling under nonboiling conditions was shown to increase with increasing pressure.