Research in the field of science communication started emerging about 50 years ago and has since then matured as a field of academic enquiry. Early findings about research-active authors and countries reveal that scholarly activity in the field has traditionally been dominated by male authors from English-speaking countries in the West. The current study is a systematic, bibliographic analysis of a full sample of research papers that were published in the three most prominent journals in the field from 1979 to 2016. The findings reveal that early inequities remain prevalent, but also that there are indications that recent increases in research outputs and trends in authorship patterns ― for example the growth in female authorship ― are beginning to correct some of these imbalances. Furthermore, the current study verifies earlier indications that science communication research is becoming increasingly institutionalised and internationalised, as demonstrated by an upward trend in papers reflecting cross-institutional collaboration and the diversity of countries where authors are based.