Telepsychiatry is increasingly used for mental health triage, but real-world implementation remains underreported, and barriers include technical reliability, patient trust, privacy and coordination across levels of care. Objective To describe and evaluate an app- and video-based triage service, Immediate Psychiatry (IP), implemented in Region Stockholm, Sweden, focusing on service use, patient characteristics, acceptability, feasibility and team experiences. Methods Adults (>= 18) registered with participating primary care centres accessed IP via the regional health app, completed a digital brief screening questionnaire, and had a 45-min video consultation with a mental health professional. A mixed-methods design was employed combining medical-record abstractions, a patient-satisfaction survey, interviews with the IP team and a clinician acceptability questionnaire administered to primary care clinicians. Quantitative data were analysed descriptively; qualitative data underwent content analysis. Results A total of 172 participants were included, predominantly presenting with stress-related, depressive and anxiety disorders. High patient satisfaction was reported for IP, particularly in terms of ease of contact, patient involvement and respectful treatment. The IP team described that the triage process was challenging yet meaningful, relying heavily on an interprofessional team with strong clinical expertise and a person-centred approach. Improved integration with regular care could further enhance the service. The response rate among primary care clinicians was low, with responses indicating moderate acceptability. Conclusions Telepsychiatry for triage delivered through a regional app was feasible, acceptable and may improve access to timely assessments. The findings also highlight important organizational and implementation challenges, particularly regarding integration with primary care, which should be addressed alongside evaluations of long-term outcomes, healthcare use and costs and policy barriers in future studies.