Structural and dynamical analyses have been used to investigate the stress field that produced the present volcano-tectonic setting of Campi flegrei caldera (Southern Italy). Although the general deformation field is highly complex, data from recent geological and geophysical surveys indicate the presence of a strong radially-symmetric component due to a local source, and only a weak (or absent) component attributable to a regional stress field. The relation between the present strain field and volcano-tectonic structures within the caldera has been further examined by dynamical analysis of seismic and ground deformation data gathered during the 1970-72 and 1982-84 bradyseismic crises. No evidence was found to support a significant dynamical control by the local volcano-tectonic structures (in particular "La Starza" and the Capo Miseno-Baia complex). It is therefore proposed a) that development of the present strain field has been dominated by the action of magmatic bodies at shallow depths, and b) that dynamical evolution of the stress field has not been focused along specific volcano-tectonic structures within the caldera.