To understand the influence of ocean in carbon biogeochemical cycle and their consequences in global climate changes advances of ocean-color satellite mission has progressed beyond the estimation of chlorophyll-a concentrations. One of recent products provided by NASA is particulate organic carbon (POC) concentration. To evaluate the performance of standard NASA POC algorithm (Stramski et al. 2008) in coastal and oceanic areas of the Southwestern Atlantic Ocean, comparisons of simultaneous in situ and satellite POC determinations were carried out in this paper. The results indicate that the POC algorithm overestimate in situ data. Nevertheless, the algorithm proved to be satisfactory in estimate POC concentrations, both in coastal and oceanic areas, moreover, to be an important tool to investigate the spatial and temporal variability of POC in the global oceans. However, the necessity of increase the efforts in collect in situ data is unquestionable and essential to improve the results of algorithm validation processes.