The economic dimension of science has been one of the most treated problems in economics during the past three and a half decades. Over 6,000 publications appeared on the assessment of research results; several hundred formulae have been proposed to measure the efficiency of research workers, research institutions, and of science as a whole. The different aspects of research activity and its role in the realization of social goals have also been clarified. However, the overall economic theory of research efficiency is still in its formative stage. The number of studies of agricultural efficiency increased in parallel with agriculture's share in the economy, the growth of society, and with the amount of resources allocated to development of agricultural production. During the past decade, considerable progress has been made in clarifying the approach to estimation of research efficiency in agriculture, using agricultural economic analytical techniques, and identifying factors affecting efficiency growth in research and innovation. This paper presents some ideas related to scientific efficiency in agricultural research. It also estimates the economic efficiency of wheat selection in Bulgaria.