Background Spiritual Well-Being (SWB) is an important aspect of health. Since soldiers, as members of community, are faced with numerous spiritual, psychological, and physical problems, belief in spirituality can play an important role in explaining their purpose in life (PIL). Therefore, this study aimed to evaluate SWB, PIL, and the relationship between these two concepts in conscripts. In this cross-sectional study, 301 soldiers were selected by available sampling method from one of the military barracks in Iran 2019. Data were collected using the demographic, SWB, and PIL questionnaires. The results showed that SWB of the soldiers were at the high level (100.6 ± 12.30) and their PIL were at the moderate level (112.92 ± 13.70). Furthermore, a direct and intermediate relationship was observed between the soldiers' SWB and PIL (P <0.001, r = 0.50). Based on the findings, increased SWB enhanced PIL in soldiers and vice versa. To increase generalizability of the data, studies over a larger statistical population are recommended in different cultures. Findings of this study can also identify the interventional strategies to increase the soldiers' purpose in life.