- environmental uncertainty,
- effect size,
Opportunism is known to have detrimental effects on firm performance. Hence, this is important to investigate factors that reduce opportunism. This study aims to examine the effects of guanxi, environmental uncertainty, and management culture on opportunism in China. A questionnaire survey of 211 Chinese dealer companies reveals that guanxi reduces dealers' opportunism and this negative relationship is stronger among firms adopting a Chinese management culture. Environmental uncertainty shows positive effect on opportunism but the relationship is weakened by guanxi. The findings also suggest that the moderating effect of guanxi may be strengthened in the presence of a Chinese management culture.