The aim of this study is to investigate the polycodedness of a Spanish scientific text as a result of interaction between codes of different semiotic systems and discourses. A polycode text focuses the fact of interaction of different codes, i.e. symbols, systems of symbols, signs and rules of their combinations with each other for the transmission, processing and storage of information in the form most adapted thereto. This term describes the phenomenon of textual heterogeneity at the level of form achieved through a mix of different semiotic systems, such as verbal and visual. In this sense, the phenomenon of polycodedness is directly related to the manifestations of interdiscursiveness. A particular attention is given to the synthesis of verbal and non-verbal means of communication, the consideration of polycode scientific texts in terms of their constituent cognitive structures that help to identify the essential properties of scientific text. The discursive and communicative approaches, being the leaders within the modern linguistics, comprise the methodological base of the research. At each stage of work, the methods that best meet the goals and objectives of the research were involved. Such methods include a discourse analysis, a method of classification and systematization, a method of quantitative analysis followed by a qualitative interpretation of the data. The emergence of a semiotically complicated text, in which the author’s intention is realized simultaneously using both a verbal code and a variety of non-verbal means, is an evidence of major changes in the modes of transmitting information about the world. The material study is based on research papers and dissertations in Spanish on various branches of scientific knowledge defended at the Autonomous University of Madrid (Spain). © 2017, Australian International Academic Centre PTY LTD. All rights reserved.