Since the appearance of AIDS, the study of this disease has generated a large amount of information and an extensive related vocabulary comprised of new terms or terms borrowed from other scientific fields. The urgent need to provide names for newly described phenomena and concepts in this field has resulted in the application of terms that are not always appropriate from the linguistic and scientific points of view. We discuss the difficulties in attempting to create adequate AIDS terminology in the Spanish language, considering both the general problems involved in building any scientific vocabulary and the specific problems inherent to this activity in a field whose defining illness has important social connotations. The pressure exerted by the predominance of the English language in reporting scientific knowledge is considered, and the inappropriate words most often found in a review of current literature are examined. Finally, attending to the two most important criteria for the creation of new scientific terms, accuracy and linguistic correction, we propose some well thought-out alternatives that conform to the essence of the Spanish language.