The present research aimed to study perceived family environment and positive mental states viz. happiness, optimism and hope among the adolescents of two different cultures, Iran and India. The total sample comprised 400 adolescents aged 16-19 from Iran and India; Out of which, half were males and half were females. Family environment scale, The Oxford Happiness Questionnaire, Adult Trait Hope Scale, and The Life Orientation Test were performed and raw scores were subjected for various statistical analyses viz. Results clearly show that the family environment dimensions viz. Relationship, Personal Growth (Goal Oriented), and System Maintenance, are correlated with positive mental states viz. happiness, optimism and hope among the adolescents of the two above-mentioned cultures. It was also shown that there are cultural and gender differences among the studied variables.