Objective: Given high relapse rates and residual symptoms in depression, new strategies to increase treatment effectiveness are required. A promising avenue is to investigate how electronic momentary assessment technology may contribute to clinical assessment and interventions in depression. Method: A literature search was conducted focusing on the potential contribution of momentary assessments to clinical applications in depression. Results: Momentary assessments are able to reveal subtle, small but repetitive and relevant patterns of emotional expression that predict future course of depression. A momentary assessment tool may expose manageable pieces of daily life behaviour contributing to the depressive experience that patients can influence. The use of this explicit knowledge of daily life experience is understudied with regard to its contribution to diagnostic assessment, monitoring of treatment effects and feedback interventions in depressed patients. The clinical application of momentary assessments may stimulate a shift from passive consumption of treatment to an active role for patients in their recovery and increased patient ownership. Conclusion: The precise, prospective and fine-grained information that momentary assessment technology provides may contribute to clinical practice in various ways. Future studies should examine the clinical impact of its use and the feasibility of its implementation in mental health care.