To determine whether professional self-perception of nurses in Mongolia improves following an educational intervention and to identify differences in scores among participant subgroups. A prospective observational pre-post design. Using a convenience sample of 67 nurses in Mongolia in 2019, the Nursing Professional Values Scale-3 instrument was used pre- and post-intervention. Independent and paired sample t-tests were conducted. Data were analysed using IBM SPSS 28.0.1.1 and Stata/SE 16.1. This study complied with the STROBE checklist. Of the 67 nurses, 92.0% were female, mean age was 32.15 years (SD 8.96), 70.0% held a bachelor's degree, 58.0% had 5 or more years' nursing experience and 51.0% were members of a professional nursing organization. After participating in the educational training, nurses reported higher overall professional self-perception as well as across subscales: activism, professionalism and caring. Considering the nursing shortage in lower-middle-income countries, it is important to recognise the influence of nurses' professional self-perception on nursing retention. This study highlights the significant role continuing educational opportunities play in increasing nurses' professional self-perception. It is imperative to explore ways of improving this perception and focusing on subgroups of nurses to help guide the use of limited resources. Further research is necessary to include nurses in other areas of Mongolia. Accurately assessing nursing professional self-perception and providing educational opportunities could improve nursing professional self-perception, nursing satisfaction, patient safety and nursing retention in lower-middle-income countries. What problem did the study address? This study meets the need for current study on the nursing professional self-perception of nursing from the perspective of nurses in Mongolia. It addresses the dangerous nursing shortage in Mongolia by determining if an educational intervention could improve nursing professional self-perception and thus improve nursing job satisfaction and retention. What were the main findings? Mongolian nurses in this study scored in the top quartile of the NPVS-3, indicating a baseline high NPSP. Educational intervention (including translated oral education and written clinical pathways) significantly improved the nurses' professional self-perception. Nurses were eager for training in other clinical and leadership topics. Where and on whom will the research have an impact? This research can be impactful for nurses, nurse leaders and policy makers in low- and lower-middle-income countries. Specifically for nurses in Mongolia, with increasing technologies and services such as cardiac catheterization laboratories becoming available, more education in these nursing specialty areas is imperative. Professional Nursing Organizations are poised to foster more educational offerings to their members and to increase membership. Nursing education provided by international volunteer nurses with Non-Governmental Organizations can improve NPSP in nurses in LMICs. This study complied with the STROBE checklist. No patient or public contribution.