This article reports Attachment Q-set data and Strange Situation classifications of 58 1-year-old middle-class infants. Security, dependency, and sociability were scored from Q-sort reports of home observations. The primary analyses involve comparisons between securely attached infants (Group B) and anxiously attached infants (Groups A and C combined). Additional analyses compare anxious-resistant with anxious-avoidant infants. Secure classification in the Strange Situation was associated with quality of secure-base behavior at home (i.e., higher Q-sort security scores) and with sociability, but not with dependency scores. Descriptive analyses of individual Q-set items support the secure-base interpretation of Strange Situation security classifications. Relations between home security scores and interactive behavior scores from the Strange Situation were also examined by multiple regression analysis.