ENThis study explores the phenomena of personal growth under stress and investigates the mediating effect of leadership and four elements of group cohesion (social, task, norm, and psychological). Data were collected at the beginning and end of mandatory military training in two units (n = 184), where the first unit was redeployed (transferred from one location to another) in the middle of the training period, and the second remained in the same physical place throughout the training period. Unit leadership and cohesion were found to mitigate the negative effect of perceived stress on personal growth; however, this effect depends on the phases of group dynamics. The modeling of structural equations revealed that social cohesion is a particularly important mediator (impact 71%) in reducing the negative impact of perceived stress on personal growth in a unit without redeployment. Meanwhile, leadership is an important mitigator when a group is in formation (at the beginning of mandatory military training, leadership mediates 15–18% of effects), as well as in the unit where the bonds between group members are weak due to physical disturbance while redeploying the unit to a new location (at the end of service, the effect of leadership is 38% in the redeployed unit).We conclude that leadership can replace a lack of social cohesion in a group with weak ties between group members and reduce the negative effect of perceived stress on personal growth. This is a new insight that allows social cohesion and leadership to be seen not only as complementary factors in group dynamics, but also as substitutes. Keywords: group cohesion; leadership; perceived stress; personal growth; military training; conscripts; structural equation modeling. [From the publication]