Within 5 years of their first conviction for a sexual offense, 10 percent had an additional conviction, and another 12 percent were convicted of a violent offense. Estimates based on five cohort samples of men born between 1953 and 1973 suggested a minimum of 260,000 men aged 20 and over in the 1993 population had been convicted of a sexual offense. For more serious sexual offenses, 1 in 90 men born in 1953 had a conviction for such an offense by age 40. If requirements of the Sex Offenders Act of 1997 had always been in force, an estimated 125,000 men in the 1993 population had a conviction that would have required registration. For 25,000, this registration would have been for life; 10,000 had a conviction in the preceding 10 years that would have required registration for up to 10 years. At least 110,000 men in the 1993 population had a conviction for an offense against a child. Of these, 100,000 would have been required to register; for 15,000, this would have been for life. About 5,000 had a conviction in the preceding 10 years that would have required their registration for up to 10 years. 4 references, 5 notes, 1 table, and 2 figures