After analyzing the transformations in Lithuanian and Ukrainian economy, the integrated regional policies effect to regional differences development evaluation methodology was prepared, which is designed to link regional developments with regional policies. The purpose of the article is to present a common Lithuanian -Ukrainian assessment methodology developed in the scientific study, which ensures the objectivity and applicability to solve regional development issues. Summarizing the variety of development level indicators in the scientific literature and experience of Lithuania and Ukraine, four main groups of indicators are identified in this paper that accurately describe the socio -economic situation: demographic, social and economic development and labor market, assessed region's transportation systems and social and tourism availability, compared public infrastructure and services development indicators. Analysis of scientific literature, Lithuanian and Ukrainian experience, statistical data analysis, and expert evaluations carried out in both countries created a joint region competitiveness evaluation system. Performed evaluation of expert opinion consensus enabled to select the indicators of region's development level evaluation and their combinations, which are necessary to carry out inter-regional comparisons. The article also contains structure graph, dedicated to indicate the consistency in the execution of the evaluation process and opportunities of use of research data analysis methods to implemented regional policies development impact to region development deficiencies calculation. The findings of the article show that the effects of implemented measures of regional policy can be evaluated only in a few years by adding investment in business, human resources, infrastructure development, but it must be done periodically to monitor regional socialeconomic development processes and the effectiveness of regional policy changes.