Introduction: This article has two purposes. First, to show the correlation between two unfortunately very common academic habits: procrastination and cheating. Second, to analyse the sequential trend of these two tendencies, from the final year of compulsory secondary education (in Spain 4th year of ESO; age 16) to the final year of university (age 22). Method: The participants in the study are 171 female students from public and private schools in Barcelona (Spain). During the research they were in 4th year of ESO, 2nd year of baccalaureate, 1st year of university, and 4th year of university, respectively. All of them were individually interviewed and administered with self descriptive questionnaires about academic cheating and academic procrastination. In order to find connections between variables and to identify differences between groups bivariate two-tailed Pearson correlations and ANOVA's series were calculated for the collected data. Results: As expected both procrastination and cheating highly and negatively correlate with academic grade. Besides, the connection between the two variables, cheating and procrastination is positive and moderate. Otherwise, the incidence of both habits is low in ESO, showing a sudden and striking rise in the final year of baccalaureate -which can also be observed in the first year of university- and a dramatic drop in the final year of tertiary education, just before graduation. Discussion and Conclusion: In summary, our data show that the transition years from secondary school to university (ages 18 and 19) are the worst in terms of the students' propensity to procrastinate and cheat, two characteristics which significantly contribute to weaken academic learning. According to the results, special support for students in these two academic years should be offered to stop or at least to reduce the reported developments. (Contains 2 tables and 2 figures.)