This study aimed to determine the effectiveness of cognitive-existential group therapy on spiritual health and image of God of parents of children with cancer using semi-experimental with pre - posttest control group was randomly assigned  and by following up has done during six-month. For this purpose 30 parents (From 24 to 54 years old) that their children due to cancer were in Mahak hospital under medical treatment and had volunteered to participate in counseling programs, Were assigned randomly to two experimental and control groups. Before the therapeutic intervention, both groups with spiritual health questionnaire (1982) and religious status questionnaire RSI (2003) were evaluated. The experimental group participated in twelve 90-minute sessions of cognitive-existential therapy that attended 2 sessions per week, while the control group did not use any psychological intervention during this period. After treatment, both groups were evaluated with the above tests. This assessment was carried out for the experimental group separately within 6 months of treatment. The data were processed by using software SPSS-16 for performing statistical test of covariance analysis (ANCOVA). The results revealed a significant difference in the spiritual health and positive impression of God in the two groups in favor of the experimental group (05/0> p), respectively. These results still remained in a 6-month follow experimental group for both variables, and showed that cognitive-existential therapy can be effective to increase spiritual health and create a positive impression of God in parents of children with cancer.