A total of 2192 articles published in the international literature with UNAM (National University of Mexico) first author affiliation and registered by the CICH (Centro de Iformación Científica y Humanística) BIBLAT database from 1978-mid-1987 were included in our analysis. Distribution of articles according to the main subject areas of the 692 different journal titles used was as follows: Physics 24.1%, Medicine 19.7%, Biology 19.4%, Chemistry 9.7%, Engineering 8.9%, Exact Sciences 7.3%, Geosciences 4.7%, Psychology 0.96%, Agrosciences 0.27%. Thirty-seven percent of articles were published in journals with a known impact factor for 1987 of 1, 46.1% (920) in journals within the range of >1–3 average citations/article and only 16.4% (327) in those titles with a factor >3. Fifty-four percent (1082) of studies appeared in journals whose total citation count for 1987 was 5000; 7.3% (146) in journals cited >50,000 times in that same year. UNAM scientists therefore as a group tend to publish in journals whose articles are not frequently cited in subsequent publications thus limiting their impact and visibility in the international scientific literature.