Expectancies on the marijuana consumption effects have been associated with initiation, frequency and intensity of this drug use. The Marijuana Effect Expectancy Questionnaire (MEEQ) is one of the most used instruments to measure expectancies. Nonetheless, there is no consensus regarding the factors of the MEEQ and there is no Spanish version. The purpose of this study was to adapt and analyze the psychometric properties of the MEEQ in 1,015 public school students from Metropolitan Lima (52.12% males), ages 13 to 18. Factor analysis grouped items into two factors: Positive and Negative Expectancies. Cronbach's alpha was high for both factors (α =.94,.92). In conclusion, the Spanish version of the MEEQ constitutes a useful measure of adolescent's marijuana consumption expectancies.