Providing Mental Health and Psychosocial Support interventions (MHPSS) for forcibly displaced Ukrainians in Central and Eastern Europe poses numerous challenges due to various socio-cultural and infrastructural factors. This qualitative study explored implementation barriers reported by service providers of in-person and digital MHPSS for Ukrainian refugees displaced to Poland, Romania and Slovakia due to the war. In addition, the study aimed to generate recommendations to overcome these barriers. Semi-structured Free List and Key Informant interviews were conducted using the Design, Implementation, Monitoring and Evaluation protocol with 18 and 13 service providers, respectively. For in-person interventions, barriers included stigma, language, shortage of MHPSS providers, lack of financial aid and general lack of trust among refugees. For digital MHPSS, barriers included generational obstacles, lack of therapeutic relationships, trust issues, and lack of awareness. Recommendations included advancing public health strategies, organizational interventions, building technical literacy and support, enhancing the credibility of digital interventions and incorporating MHPSS into usual practice. By implementing the recommendations proposed in this study, policymakers, organizations and service providers can work towards enhancing the delivery of MHPSS and addressing the mental health needs of Ukrainian refugees in host countries, such as Poland, Romania and Slovakia.