BackgroundThe ubiquitous nature of mobile phones and their increasing functionality make them an ideal medium for the delivery of large-scale public health information and interventions. While mobile phones have been used to this end in behavioural and physical health settings, their role in monitoring and managing mental health is in its infancy. Aims The purpose of this paper is (1) to provide an overview of the field of mobile mental health and (2) by way of illustration, describe an initial proof of concept study carried out to assess the potential utility and effectiveness of a newly developed mobile phone and web-based program in the management of mild-to-moderate stress, anxiety and depression. Methods Over 6 weeks, participants were given access to “myCompass”: an interactive self-help program, which includes real-time self-monitoring with short message service prompts and brief online modules grounded in cognitive behavioural therapy. Results Preliminary analyses found that participants' symptoms of stress, anxiety, depression and overall psychological distress were significantly reduced after using myCompass. Improvements were also found in functional impairment and self-efficacy. Conclusions These preliminary results support the feasibility of implementing mobile phone-based interventions with the potential of improving psychological wellbeing.