We analyse the science and technology news reports covered by the Jornal Nacional, the Brazilian newscast with the largest audience, which is broadcast at prime time on a free-to-air channel. The constructed week methodology was used to compose a sample of 72 newscasts, representative of an entire year (from April 2009 to March 2010): 77 science and technology news reports were thus identified, occupying an average of 7.3% of the newscast's daily broadcasting time, and therefore giving evidence that such matters belong on the JN's agenda. Content analysis has enabled us to observe the following: most reports were focused on announcing research results; the main fields dealt with were medical science and health; the coverage of national research projects ranked highest; researchers and scientific institutes represented the main sources of the news items; scientists were mostly shown in their offices, and as far as interviews are concerned female scientists were a minority. The approach to science was more positive than negative and controversial aspects were scarcely explored.