There are several types of epidemiological designs and they can be organized in levels of evidence. These designs are divided in observational and experimental. The observational studies can be cohort, case control and cross sectional studies. The experimental studies are the clinical trials. Due to the importance of the meta-analysis they will also be mentioned. All the articles published in the Ecuadorian Journal of Neurology were gathered since its first edition in 1992. During these 17 years, 271 articles have been published from which 94 are original articles. Clinical trials represented 12.8% of all the original articles. A decrease in the number of series reports and an increase of cohort and cross sectional studies was observed. From 1992 to 2004 most of the articles were from national authors but then, foreign authors represented the higher percentage. We think it is very important to promote the national production especially of clinical trials because they would provide a better evidence and, more importantly, evidence that could be applied to the Ecuadorian population.