The Gulf of Naples (GoN) is an important sub-basin of the Mediterranean Sea, with hydrological features typical of both oligotrophic systems (in its offshore area) and eutrophic coastal zones. In addition, the GoN is subject to severe anthropic impacts (e.g., pollutant discharges, improperly treated sewage, maritime traffic, etc.) which might compromise the water quality and the state of the marine ecosystem. Owing to such high variability and complexity in the hydrodynamic and biogeochemical processes, the GoN represents a natural laboratory to investigate the interactions between physics and biology. Since the late 1970s, an increasing number of investigations has been carried out to study the circulation and hydrology of the GoN, as well as the annual and interannual dynamics of phyto-and zooplanktonic organisms. As to ecosystem dynamics studies, the GoN hosts a unique site, the Long Term Ecological Research Station MareChiara of the Stazione Zoologica "Anton Dohrn", where environmental parameters (T, S, O2, nutrients, Chl, HPLC pigments) and plankton communities (phytoplankton, microzooplankton, mesozooplankton) have been sampled at a weekly frequency since 1995, whereas from 1984 to 1991 sampling used to be biweekly. With specific reference to the circulation, while early studies were limited by technological hindrances, in very recent years the installation of a network of high frequency coastal radars has allowed a very detailed synoptic description of the surface current field in the GoN. In this review we will first provide a summary of the knowledge of the physical and biological dynamics of the GoN, and then we will focus on the seasonal features of the surface circulation and plankton dynamics. These results confirm the necessity of an integrated multiplatform monitoring of coastal areas for a proper understanding of marine ecosystems.