Today, mobile phones play a key role in the communication of different countries and it provides a wide range of possibilities for its users [1]. China's mobile usage as the world's most populous country in 2016 reached over 695 million users, representing 10% annual growth [2]. Overuse of cell phones, like any other technology-related phenomenon, also has its disadvantages [3]. Many researchers believe that overuse of the cell phone in the minds and nerves of users causes a form of addiction that is just as destructive as drug addiction, alcohol, eating much, computer games and the Internet [4]. Mobile phone addiction is a widespread problem among adults around the world [5]. Addiction to his cell phone shows up while doing other things including study, driving, cycling and even sleeping [6]. International research shows that about 6% of mobile phone users are addicted to it [7]. In Iran, the prevalence of mobile phone addiction has been relatively high, for example, Background and Purpose: Overuse of the mobile phone, like any phenomenon related to other technologies, also has its disadvantages and Causes personal, social, and psychological problems such as depression, hopelessness, anxiety, stress, sleep disorders, and social isolation. Method: This is a cross-sectional study. Statistical population included high school students in Divandareh city (Kurdistan Province, Iran) and sample size according to Cochran formula was estimated 384 students. Data was collected using a demographic questionnaire and a standard mobile addiction questionnaire, Beck Depression and Beck Hopelessness Questionnaire. Data was entered into SPSS-21 software and analyzed by t-test, chi-square and ANOVA. Findings: In the present study, out of 370 high school students in Divandareh city, 54% (198 students) were boys and 46% (172 students) were girls. According to the chi-square test, there was a significant relationship between depression and hopelessness with mobile phone addiction (P<0.001). There was also a significant relationship between sex and mobile phone addiction (P=0.004). On the other hand, according to ANOVA test, no significant relationship was found between age and mobile phone addiction (P=0.601). Conclusion: The results of this study show that traumatic and excessive use of mobile phones is a potential risk factor for mental disorders in students and such disorders are in turn an effective factor in decreasing students' academic performance. The purpose of this study was to determine the relationship between mobile phone addiction and depression and hopelessness and its prevalence among high school students in Divandareh city.