The city of Cartagena (Colombia) reports a high maritime transport activity, due to its industrial zone and the location of one of the country's main export ports. This can cause the presence of environmental contaminants, such as the polycyclic aromatic hydrocarbons (PAHs). Colombian regulation (Res. 0631 of 2015) establishes a limit of 0.01 ppm for these contaminants. In this study, sediments and surface water were collected from six monitoring stations at the Bay of Cartagena. Physico-Chemical parameters, such as total organic carbon, organic matter, pH and PAHs were analyzed from these samples. Although previous studies have reported the presence of PAHs in this bay, it was not possible to determine traces of these contaminants from the samples collected in this study. However, it was observed a pH values from 7.2 to 8.3, and a maximum organic material of 89.60 mg/L for station E5. A careful analysis of these results allowed us to understand the reasons for not having found PAHs even in water samples, meaning that some properties such as the content of organic carbons, pH and particle size are affecting the stability of PAHs in the marine system, causing their migration to soils in the coastal or even in deeper points than the superficial sediments in the water columns.