The study of journal authorship and editorial board membership from a gender perspective is addressed in this paper following international recommendations about the need to obtain science and technology indicators by gender. Authorship informs us about active scientists who contribute to the production and dissemination of new knowledge through journal articles, while editorial board membership tells us about leading scientists who have obtained scientific recognition within the scientific community. This study analyses by gender the composition of the editorial boards of 131 high-quality Spanish journals in all fields of science, the presence of men and women as authors in a selection of 36 journals, and the evolution of these aspects from 1998 to 2009. Female presence is lower than male presence in authorship, editorial board membership and editorship. The presence of female authors is slightly lower than the presence of women in the Spanish Higher Education sector and doubles female presence in editorial boards, which mirrors female presence in the highest academic rank. The gender gap tends to diminish over the years in most areas, especially in authorship and very slightly in editorial board membership. Large editorial boards and having a female editor-in-chief are positively correlated with women presence in editorial boards. The situation of women in Spanish science is further assessed in an international context analysing a selection of international reference journals. The usefulness of journal-based indicators to monitor the situation of men and women in science and to assess the success of policies oriented to enhance gender equality in science is finally discussed.