The Revela13 surveillance system was launched in April 2012 in the Bouches-du-Rhône department. The goal was to test methods for identifying and geolocating new cases of these cancers and to conduct spatial analyses to identify potential clusters of cases within the region. Data collection was based on reports from clinicians regarding targeted cancer cases, supplemented by data extracted from multidisciplinary team meeting (MDT) records from cancer coordination centers. After three years of data collection, a capture-recapture study covering the 2013–2014 period was conducted to assess the comprehensiveness of the Revela13 registry, using data from the Medical Information Systems Program (PMSI) and data from anatomic cytopathology laboratories (ACP) as supplementary sources. A two-source analysis (Revela13 and PMSI) was performed for acute leukemias and a three-source analysis for urinary tract cancers. The two complementary data sources made it possible to identify 15% (urinary tract cancers) to 20% (acute leukemias) of additional cases over the 2013–2014 period. The estimated number of cases was 232 [95% CI: 225–239] for acute leukemias, 1,247 [1,239–1,255] for urothelial cancers, and 600 [589–611] for kidney cancers. The completeness of the registry without stratification was 76% [74%–79%], 84% [83%–85%], and 84% [83%–86%], respectively. For all three cancers, older individuals were significantly less likely to be captured by the Revela13 registry than younger individuals. For urothelial cancers, stage and area of residence also contributed to heterogeneity in capture. Finally, coverage rates varied across the regional cancer centers (RCPs) distributed throughout the country. This study provided some suggestions for improving the coverage of the Revela13 registry data, notably the routine inclusion of PMSI data and the need for better identification of older patients.