Each police force in England and Wales provided information on all persons formally cautioned for a "standard list" offense (indictable offenses and the more serious summary offenses) during 2 sample weeks: November 24-30, 1985, (2,736) and January 25-31, 1988, (2,949). The police provided the names of those cautioned and the details of the main offense for which the caution was administered, together with the number of their previous cautions, if any. To ensure that the cautioned samples were representative, they were compared with the appropriate national data in the Criminal Statistics for 1985 and 1988. The 1985 sample corresponded closely in terms of age and gender, but juveniles, especially males, were over-represented in the 1988 sample. Seventy-nine percent of the 1985 sample and 64 percent of the 1988 sample were juveniles. Eighty-three percent in the 1985 sample had no previous criminal history, compared with 77 percent of the 1988 sample. Following up the 1985 sample through the Offender's Index showed that 13 percent were convicted of a "standard list" offense within 2 years; males were almost three times as likely as females to have a conviction. The number of convictions before the 1985 caution was the factor most closely associated with conviction during the 2 years afterwards. 1 table, 1 figure, and 3 references