In October 2005, the Department of Health and Social Affairs of Saint-Pierre-et-Miquelon requested technical support from the French Institute for Public Health Surveillance to investigate a suspected excess of cancer and leukemia cases reported by the local population. An exploratory study was conducted to retrospectively measure the incidence of cancer in the archipelago and compare it to estimated or observed rates in mainland France and the Magdalen Islands (Canada). A case was defined as any invasive malignant tumor diagnosed between January 1, 1998, and December 31, 2006, in a person residing in Saint-Pierre-et-Miquelon, excluding any recurrence or metastasis. The data required for case identification were collected primarily from medical evacuation records maintained by the social welfare fund. Standardized incidence rates were calculated for all cancer sites combined and for leukemias, as well as for specific cancer sites for which the literature suggests a possible association with exposure to waste incineration fumes. We identified 233 cases of cancer on the archipelago between 1998 and 2006. We observed no significant difference in the overall cancer incidence among residents of Saint-Pierre-et-Miquelon and the French mainland population. Cancers, regardless of site, and lung cancer are less common in the archipelago than in the Magdalen Islands. In contrast, the observed incidence of acute leukemias is significantly higher in Saint-Pierre-et-Miquelon than in the reference populations. Despite the biases that may have led to an overestimation of the standardized incidence ratio for acute leukemias and the random fluctuations in disease distribution, it cannot be ruled out that these results are the consequence of exposure to one or more risk factors common to the cases. In light of this epidemiological observation, it is recommended: - to conduct a description of all cases of acute leukemia identified in the study in order to identify the possible presence of common risk factors; - to establish prospective surveillance of cancer cases on the archipelago (R.A.)