This article analyses a parallel corpus of English-Spanish complex noun phrases extracted from medical texts. The data comparing their length, pattern, and the type of solution is intended to help identify and describe the techniques used to translate English complex premodification into Spanish. The analysis shows that well-established patterns are used in such translations. Translating English complex noun phrases into Spanish often presents a challenge because there are numerous ways to make the relations explicit by means of postmodification. Identifying the regularity of these patterns is very important for specialized translation and translation training purposes.