The present study was aimed at evaluating sediment pollution and toxicity in the Bay of Pozzuoli (BoP) (Tyrrhenian Sea, southern Italy), characterized by high anthropic pressure and by previous industrial facilities. Analyses were carried out to evaluate the content of metals, total hydrocarbons (C10 - C40) and polycyclic aromatic hydrocarbons (PAHs) in sediment samples collected along five transects from the coast. Sediment samples were tested for toxicity as whole sediment (WS) suspensions to sea urchins (Arbacia lixula), or as elutriate (EL) in diatoms (Phaeodactylum tricornutum). WS-exposed sea urchin embryos and sperm underwent significant increase of developmental defects (DD), or inhibition of fertilization success and increased DD in the offspring of WS-exposed sperm. Diatoms were reared in sediment EL and the effects were evaluated as growth inhibition. Different pollution and toxicity patterns were observed along the five sediment sampling transects, without a monotonic trend vs. distance from coast, suggesting increased sediment toxicity in samples collected at intermediate distances.