The issue of persistent offenders has come into increasing prominence in recent years. This article attempts to consider whether there are changes over time in the numbers and proportions of persistent offenders. The concern is with all ages, focusing on both females and males. The study explored age, period, cohort, and gender effects in the patterns of persistent offending. The study identified both the scale of the problem and the apparent shifts in the nature of the problem. Using birth cohort conviction records, the study estimated that around 640,000 males and 54,000 females aged 46 years or under had been persistent offenders at some point in their lives. Patterns that characterize the present body of persistent offenders include: (1) both male and female offenders who are first convicted at a young age are much more likely to become persistent offenders than their older counterparts; (2) male offenders are at much greater risk of becoming persistent offenders than females; and (3) the proportion of female offenders who become persistent is increasing, and females are becoming increasingly more like males in terms of their likelihood of becoming persistent offenders. The major shifts over the past few decades include: (1) new convicted offenders are declining among the younger age groups with a similar decline in those becoming persistent offenders; (2) those convicted for the first time aged 10-14 are much more likely to become persistent offenders; (3) the number of new male offenders has stabilized among those in their 20's; and (4) the number of new convicted male offenders among those age 30 and over has increased. The study identified the dangers of overlooking the patterns among older offenders, aged 20 years or above. It is recommended that the whole area of persistent offenders be reviewed and empirical work be instigated that goes beyond the attempts to evaluate the effectiveness of some recent measures relating to persistent young offenders. Appendix and references