The use of biodegradable polymers is certainly an excellent strategy to face many of the problems related to the disposal of traditional polymers, whose accumulation in the environment is harmful and damaging. However, in order to take advantage of the characteristics of biodegradable polymers, it would be strategic to modulate the biodegradation rate of biodegradable polymers in relationship to the expected lifetime. In this view, the control of biodegradation rate is even more important than the characteristic of biodegradability itself. It is therefore very important to understand and control the transformation processes, structures and morphologies resulting from the process conditions used to produce the articles and, not least, the biodegradation. The latter is strictly dependent on the variables just mentioned. The poly-lactic acid, better known by its acronym PLA is a biodegradable polymer. Numerous studies have been carried out on the degradation process of this polymer. In this work, fumaric acid and magnesium hydroxide were added by melt compounding to a commercial PLA grade with the objective of controlling the rate of hydrolysis, and consequently the biodegradation rate. The hydrolysis process was followed, as function of time, by means of different techniques: pH variation, change of weight, DSC analysis. The samples were also analyzed in terms of biodegradability by means of a homemade respirometer apparatus, in controlled compost conditions.