We analyzed colorectal cancer incidence data from the Tuscany Cancer Registry, central Italy, for the period 1985-2005. We carried out a trend analysis through a Joinpoint regression analysis, and summarized trends as annual percent change (APC) of the standardized (European standard) rates. Colorectal incidence rates increased until 1996 (APC=+1.4, 95% CI: 0.8-1.9), then decreased significantly (APC=-1.1, 95% CI: -0.8 to -0.4). The change was detected as statistically significant in the age group of 54+ years. Among younger individuals, we observed an increasing incidence until 2003. In the same geographical area, a colorectal screening programme has been active from 1982; it was initially based on guaiac faecal occult blood testing (GFOBT) and on immunological testing (IFOBT) since the mid 1990s. The decline in colorectal cancer incidence since 1996, in the whole population and especially among individuals older than 54 years, may suggest the effect of FOBT screening in terms of precancerous polyps removal.