In Italy there are eight tumor Population-Based Registries (PBRs) that publish incidence data, and only one of them (Ragusa) provides data for Southern Italy. Usually, PBRs are based on data collection from Pathologists and medical records. Our integrated system differentiates from traditional PBRs because the information comes from the General Practitioners (GPs) and is completed with the diagnosis provided by the Pathologists (Ps). During two years we have registered 1,057 new cancers on a middle period population of 212,644. GPs and Ps signed 395 and 879 incident cases, respectively. GPs alone provided 16.8%, Ps alone 62.6%, and either source 20.6% of total cases. After excluding non melanotic skin cancers and bladder carcinoma, the GPs-Ps integrated system counted 828 new cases in two years. These incidence data are the first in our region (Puglia). The 178 cases signed by GPs alone should have been lost if the informations of our PBR had been based only on local Ps' records. Moreover, 94 of GPs cases (11% of total cancers registered) were subjects who moved outside the area for diagnosis and treatment. Even if this article evaluates the effect of under-registration attributable to Ps or GPs, the cancer incidence data and the active involvement of GPs indicate that they could be usefully involved in the registration of cancer data.