Data were taken from two separate National Crime Survey projects. Interviews were conducted in eight cities in 1972; about 60 percent followed up in 1975. Interviews were conducted in the five largest U.S. cities in 1973, and about 60 percent followed up in 1975. Including only those residents who had been asked specifically about their routine activities and excluding those from three cities whose time 1 data was unavailable, a sample of 33,773 individuals and 19,005 heads of households remained. Passive lifestyle changes (such as increases or decreases in daytime or nighttime activity outside the home) are more likely to influence victimization risks in the expected direction than are active lifestyle changes (those undertaken explicitly to reduce victimization risk). However, their impact is not uniform across type of lifestyle change or victimization. Regardless of the type of crime, those who spent the most night time outside the house were most vulnerable to serial victimization. Persons who took active precautions at time 1 were more likely than their less cautious counterparts to have been victimized at the time 2. However, reasons for taking or not taking such precautions and the fact of their subsequent victimization are both attributable to the type of neighborhood they live in. 4 tables and 22 references (Author abstract modified)