Radioecological studies have been carried out in area of Gela Phosphate Industry. As a part of the project, some achievements have been described in the paper, including: (1) determination of the activity concentrations of 210Po, 210Pb, uranium, and radium isotopes in phosphogypsum, phosphoric acid, soil, and marine sediment, (2) inventory estimation of the NORM in the residual product and by-product, and (3) the radioecological investigation and evaluation on the NORM contamination in the sea area of Gela. The obtained data showed that the 210Po, 210Pb, uranium, and radium isotope contamination due to discharge of phosphogypsum from 1960s to 1990s is not observable through sediment analyses.