This article investigates two issues that affect the lower and upper boundaries of the crime of attempt. In terms of the for- mer, the commencement of execution in completed attempts is analy- sed as a specific issue, examining positions that have defended using different inherent criteria than for incomplete attempts. With regard to the upper boundary, the article specifies the concept of complete attempt and clarifies what actually applies to punishable intent, thus setting out up to what point one can validly desist from enacting said fact. The contributions of the study are of interest both for enabling or opening up the possibility of desistance and for its pre- clusion or closure.