Study data came from interviews with over 300 convicted burglars who were on probation or incarcerated in southern England. They were all males over the age of 16. Few offenders said that they decided to offend as a result of the chance discovery of an opportunity for crime; most made the decision beforehand. The majority claimed that the decision to offend was precipitated by some specific factor, usually the need for money or the influence of others. Over half said that if they were prevented from offending in a given situation, they would give up and go home. However, many more said that they would sometimes give up, depending on the circumstances. Many said that they would attempt another offense within a few days or a few weeks. Offenders clearly chose to break the law, but it would be difficult to determine the extent to which the decisionmaking was rational. Findings offered some support for the principles on which situational crime prevention is based. Risk, reward, and ease factors are the crucial situational cues. A discussion of implications, appended tables, and a bibliography listing 111 references are supplied.