The conclusion of this study is that improved street lighting can be a feasible, inexpensive, and effective method of reducing crime and should be included as one element of a situational crime-reduction program. Results were mixed for the eight American evaluation studies. Four studies found that improved street lighting was effective in reducing crime; however, the other four found that improved lighting had no effect on crime. There were no obvious reasons for these different findings. The five more recent British evaluation studies, on the other hand, all showed that improved lighting led to decreases in crime. Their results indicated that improved lighting led to a significant 29-percent decrease in crime in experimental areas compared with comparable control areas. Taken together, the 13 studies from the United States and the United Kingdom showed that improved street lighting was linked to a significant 21 percent decrease in crime in the experimental areas compared with comparable control areas. Since these studies did not find that nighttime crimes decreased more than daytime crimes, a theory of street lighting that focuses on its role in increasing community pride and informal social control may be more plausible than a theory that relies on increased surveillance and increased deterrence. Future research should measure crime based on police records, victim surveys, and self-reports of offending. Levels of illumination, as well as crime rates, should be measured before and after the intervention in experimental and comparable control areas. Future research should also include experimental, adjacent, and nonadjacent control areas in order to test hypotheses regarding displacement and diffusion of benefits. 3 tables, appendix and 65 references