This graduation paper researches the phenomenon of country-of-origin effect with the two-fold aim to define a unified model for the COO effect evaluation and identify model application opportunities in the business reality. This identification of the aim of the paper has led to the following objectives of the study: · to present an in-depth analysis of theoretical concepts and models related to the COO effect and identify main trends in the scientific COO research, · to identify essential principals of the COO effect evaluation in regard to consumer behaviour; · to integrate main theoretical and empirical aspects of the phenomenon in a unified hypothetical model; · to propose opportunities for model application in Lithuanian business. In order to achieve the stated aim and given objectives, the object of research was defined as COO effect and the following methodology was selected: (1) content analysis of empirical research to be carried out, (2) theoretical analysis of theories related to COO to be conveyed, (3) synthesis of empirical and theoretical dimensions in a unified COO model, (4) a pilot study to be carried out to define the existence of the COO effect in regard to Lithuanian consumers. Part 1 of the paper discloses major theoretical and empirical concepts related to the COO effect. Analytical approach is used in Part 2 to view theoretical and empirical approaches to the evaluation of COO effect in consumer behaviour. Part 3 of the paper covers pilot research as an illustration of model application and a basis for suggestions for the further model application. Major findings and conclusions of the MBA paper can be summarised in the following statements: · COO effect is one of the factors influencing consumer behaviour, but its size and extent very much depend on contextual factors. · COO phenomenon covers country identity and country image. The latter is fragmented and very dynamic, thus its influence on the complexity of COO effect is considerable. · Theoretical and empirical approaches to the COO effect are integrated and unified in a hypothetical model, which is complex. Consequently, further research is necessary in this areas to test the validity and opportunities for empirical application of the model.