Abstract Background Digital addictions and their influence on mental health are being intensively studied nowadays but scientific data about Bulgaria is still scarce. The study is focused on the prevalence of nomophobia among medical students, its relationship with anxiety and motivation for seeking professional help. Methods The cross-sectional study included 369 medical students, age 19-34 (mean 23) years. We analyzed the whole group and subgroups of Bulgarian/foreign students and second-/sixth-year students. Data were collected by a self-administered questionnaire including smartphone addiction scale (SAS) with a 4-point Lickert scale, a 7-item generalized anxiety disorder scale and socio-demographic questions. Results The prevalence of mild smartphone addiction was 55% and of moderate one 30%. The dependency score was higher in the groups with a moderate and severe level of anxiety (P < 0.001). There was no difference in dependency score by age and gender but it was higher among foreign students compared to Bulgarian students and lower in the sixth-year group compared to the second- year one. The anxiety score was higher in females compared to males and among second-year students compared to the sixth-year (P < 0.001). Only 40% of males and 50% of females reported motivation to look for professional help. Conclusions The prevalence of smartphone addiction is high among both Bulgarian and foreign medical students. Our results reveal co-morbidity of smartphone addiction and generalized anxiety disorder. The low motivation to consult a specialist points out underestimation of the problem. Implementation of educational programmes, individual and group therapy can help young people to curb smartphone use. Key messages Smartphone addiction is related to increased anxiety level and affects adversely mental health. The establishment of a healthy relationship between young people and technologies has to be considered as part of health promotion.