This study examined how values and their congruence with classmates' values relate to psychological adjustment in 460 Estonian adolescents (M[subscript age] = 12.95 years). Participants rated the importance of openness to change, conservation, self-enhancement, and self-transcendence values and their psychological adjustment in seven dimensions. Personal self-transcendence values were positively related and self-enhancement values negatively to adolescents' psychological adjustment. Conservation and openness to change values were linked to specific psychological adjustment dimensions. Values at the personal and classroom level showed contrasting effects. Important nonlinear associations emerged as well. Endorsing openness to change at an average level was associated with higher emotional stability, but endorsing conservation and self-enhancement at an average level with poorer adjustment--negative self-esteem and dependence, respectively. The congruence between personal and peer values was unrelated to adolescents' psychological adjustment. The findings point out the importance of not only adolescents' personal values but also peer values regarding adolescents' psychological adjustment.