Online career counseling is an important new horizon for vocational guidance. The present study investigates the role of online career counseling and of psychological capital and hardiness on career decision making. The research population included all Tehran students in 2019. After random selection, 30 students each were assigned into either the online counseling group or the control group. After online counseling, intervention students had higher scores than the control group on career decision-making. In the intervention group (but not the control group), students with higher hardiness and psychological capital had higher scores on career decision-making.