BACKGROUND: Implementation of psychosocial interventions in mental health services has the potential to improve the treatment of psychosis spectrum disorders (PSD) in low- and middle-income countries (LMICs) where care is predominantly focused on pharmacotherapy. The first step is to understand the views of key stakeholders. We conducted a multi-language qualitative study to explore the contextual barriers and facilitators to implementation of a cost-effective, digital psychosocial intervention, called DIALOG+, for treating PSD. DIALOG+ builds on existing clinician-patient relationships without requiring development of new services, making it well-fitting for healthcare systems with scarce resources. METHODS: Thirty-two focus groups were conducted with 174 participants (patients, clinicians, policymakers and carers), who were familiarized with DIALOG+ through a presentation. The Southeast European LMICs included in this research were: Bosnia and Herzegovina, Kosovo, (Kosovo is referred throughout the text by United Nations resolution) North Macedonia, Montenegro and Serbia. Framework analysis was used to analyse the participants' accounts. RESULTS: Six major themes were identified. Three themes (Intervention characteristics; Carers' involvement; Patient and organisational benefits) were interpreted as perceived implementation facilitators. The theme Attitudes and perceived preparedness of potential adopters comprised of subthemes that were interpreted as both perceived implementation facilitators and barriers. Two other themes (Frequency of intervention delivery; Suggested changes to the intervention) were more broadly related to the intervention's implementation. Participants were exceedingly supportive of the implementation of a digital psychosocial intervention such as DIALOG+. Attractive intervention characteristics, efficient use of scarce resources for its implementation and potential to improve mental health services were seen as the main implementation facilitators. The major implementation barrier identified was psychiatrists' time constrains. CONCLUSIONS: This study provided important insights regarding implementation of digital psychosocial interventions for people with PSD in low-resource settings by including perspectives from four stakeholder groups in five LMICs in Southeast Europe - a population and region rarely explored in the literature. The perceived limited availability of psychiatrists could be potentially resolved by increased inclusion of other mental health professionals in service delivery for PSD. These findings will be used to inform the implementation strategy of DIALOG+ across the participating countries. The study also offers insights into multi-country qualitative research.