Starting from January 1997 we prospectively evaluated all cases of acute hepatitis B admitted to two of the main Infectious Diseases Units in Catania (eastern Sicily). The survey was extended throughout a 10-year period up to December 2007. Between 1997 and 1999 we observed 21 cases of acute hepatitis B; between 2000 and 2002 18 cases; between 2003 and 2005 22 cases and, finally, 37 cases were reported in the period 2006-2007. We found an increase in acute hepatitis B cases among people aged 26 to 44 years (from 38% in 1997-99 to 70% in 2006-07). A progressive decrease in intravenous drug abuse as a risk factor for acute hepatitis B was also observed (from 61% to 14%) together with a parallel increase in cases due to sexual transmission (from 19% to 56%) and outpatient cosmetic surgical procedures. Mean time to serum HBsAg negativization was longer in the last period (2006-07), with 6 cases out of 37 showing HBsAg persistence beyond 12 months from the clinical onset. Furthermore, in 2006-07 there were 12 cases (42%) of acute hepatitis due to HBV genotypes A and F. In our area, a progressive drop of hepatitis B cases due to intravenous drug abuse occurred, whereas heterosexual and iatrogenic cases increased. Cases due to HBV non-D genotypes may well be related to migration from endemic areas towards Sicily.