Presentation of an enquiry held on 17 establishments in order to assess the weight of chemical joumals in university libraries. According to the lists of the Chemical abstracts and of the Science citation index, there is a hard core of 800 important titles. In libraries, chemistry covers 15 to 25 % of the titles, that is 30 to 60 % of the subscription budget ; in absolute value, this means 30 to 78 titles. Overlaping rates seem limited. The CADIST of Lyon receives 546 titles. All the loan requests have increased fivefold since 1980 and involve the most important titles first.