Little is known about the impact of individual characteristics, historical factors, and situational characteristics on youth's proactive work socialization behavior (career planning, skill development, consultation, and networking). Data from a longitudinal cross-national study (Belgium, England, Israel, Italy, the Netherlands and Spain) on career starters from two occupational groups, are used to test the hypothesized impact of predictor sets. Results confirm the positive impact of early career experience on the skill development proactive behavior; the dominant impact of the broader socioeconomic political and cultural country context on all four aspects of proactive behavior; and the sporadic effect of occupation, gender, and educational history on some proactive behavior dimensions.