The effect of the blending of crude oils on fouling propensity was investigated to determine the extent to which compatibility of crude oils influences fouling. In this study, fouling testing was performed for a series of crude oil blends with diverse compatibility as measured using a titration method. After testing, fouling deposits were recovered and analyzed. For the studied blends, the results show that compatibility is the driving force for fouling propensity. Asphaltene and inorganic contents also play a significant, but secondary role in the fouling of these samples. Filtration and temperature effects were also evaluated for some of the blends. As expected, temperature decreases fouling propensity, while filtration has a low impact indicating that, for the studied blends, fouling is temperature dependent and not driven by the presence of suspended inorganic particles. A correlation is proposed to describe the fouling propensity based on compatibility measurements of the blends at room temperature. The analysis of the deposits revealed correlations between deposit composition and blend characteristics. In particular, soot formation during fouling seems to be related to micro carbon residue in the blends. It was also found that infrared measurements can be used to estimate the formation of carbonaceous materials in the deposits. The presence of long paraffins in the deposit could have a large impact on fouling propensity and might indicate that the interaction between paraffins and asphaltenes persists even at high temperatures. The results demonstrate that compatibility measurements using titration techniques can be successfully used to minimize fouling by optimizing concentrations of the components of a specific blend.