The authors have compared individual cancer mortality records from the file of the Central Statistics Office (ISTAT) with those of the Cancer Registries of Varese and Torino for the period July-December 1976. Most diagnoses ascertained by the Cancer Registries were histologically confirmed. The results showed a high degree of reciprocal completeness (over 90%) for both systems (Cancer Registries and mortality statistics) and a satisfactory level of concordance (75% at Varese, 70% at Torino). The discrepancies, concentrated in certain nosologic codes, were analyzed. The conclusions suggest that the correspondence between mortality statistics and clinical diagnoses is high, at least in the geographical areas examined.