The asphaltene precipitation and deposition cause severe operational, economic, and environmental problems to the petroleum industry in all of its streams, such as pipe clogging, emulsion stabilization, and incrustation in separators. It is induced by temperature, pressure, and composition changes at crude oil production and refinement. The crude oil incompatibility is the main reason for asphaltene precipitation at refinery plants. Although it has been the subject of studies for the last 50 years, there is still a lack of robust and reliable tools that can detect and monitor the asphaltene precipitation online. In this scenario, the present work aims to use near-infrared spectroscopy to analyze the oil compatibility regarding asphaltene stability as well as to study the influences of pressure, temperature, and composition variation at desalter conditions. For this, a near-infrared spectrometer equipped with a transflectance probe connected to a variable volume high-pressure cell was used. The results showed that the temperature, pressure, and rate of flocculant agent addition on the crude oil presented a small influence on the asphaltene precipitation onset at the experimental range studied. The interaction among the compounds in oil blends was the only factor that changed the asphaltene stability level.