The 1979 Massachusetts law raising the legal drinking age from 18-20 is examined. The effects on the drinking, drinking and driving and nonfatal and fatal crash involvement of 16-17 yr olds, teenagers immediately younger than those targeted by the law were studied. Data from Massachusetts are compared with those from New York State, where the drinking age remained at 18. A total of 3 yr of survey data from the 2 states and 6 yr of data from the Department of Transportation''s Fatal Accident Reporting System provide for pre- and postlaw comparisons. Raising the drinking age apparently had minimal effects on the drinking behavior of Massachusetts teenagers. Although there was a significant reduction in nonfatal crashes in Massachusetts compared with New York, no decline in single-vehicle nighttime fatal crashes or in overall fatal crashes was observed. Changes in the drinking age may offer some reduction in teenage driving after drinking and traffic crash involvement, but teenage drinking and driving after drinking remain serious problems even in states that raise their drinking ages.