The present paper seeks to explore the uses of punctuation symbols in the "Booke of soueraigne medicines" (ca. 1550) written by John de Feckenham (1515 - ca. 1584). Sixteenth century punctuation in scientific manuscripts has been often the cinderella of this type of studies, since scholars have been generally interested in literary printed material and grammar books of the period (Howard, 1930; Ong, 1944; McKenzie, 1959; Salmon, 1962 and 1988; Clemens and Graham, 2007). In our analysis of the data, we will apply Lucas’s (1971) notion of sense-units in order to avoid imposing our modern view of syntax on the texts under scrutiny. Our methodological approach will also combine an analysis of genre variables in the texts within Feckenham’s volume, since earlier studies have shown that the generic structure of the texts is strongly linked to what Lucas has labelled as structural and interpretative-expository punctuation. We conclude that the uses of punctuation marks are clear and systematic for one specific text and scribe. This study will benefit later critical editions of this and similar texts.