In contrast to past consensus, many authors now feel that the passive voice compromises the quality of scientific writing. However, studies involving scientific articles are rare. Using a corpus of 60 scientific research articles from six journals, this study examined the proportion of passives used, and the contexts and forms in which they occurred. The results revealed that about 30% of all clauses were passive clauses. The canonical form was most pervasive, followed by the bare passive; together, they constituted more than a quarter of all clauses analyzed. Passives were typically used in main clauses, followed by relative and adverbial clauses. Roughly 29% of all passives were located in the methodology section. Based on the results, the proportion of passives in scientific writing may stabilize at about 30%. It is unlikely to dramatically drop any further since the trend suggests that passives are still widely used in the methodology section.