In this work, agave fibers (AF) were used as a reinforcement and azodicarbonamide (ACA) as a chemical blowing agent (CBA) for the production of bilayer materials via rotational molding. In this case, the external layer was a composite of linear medium density polyethylene (LMDPE) with different AF contents (0 to 15% wt.), while the internal layer was foamed LMDPE with different amounts of ACA (0 to 0.75% wt.). The samples were characterized in terms of thermal, morphological and mechanical properties to get a complete understanding of the structure-properties relations. The results showed that combining both AF and ACA increased by up to 56% the thickness of the parts, which is inversely proportional to the bulk density of the composites, leading to density decreases in similar proportions. In general, the addition of AF increased the tensile (23%) and flexural (29%) moduli compared to the neat LMDPE. However, lower values compared to the neat LMDPE (75% and 56% for the tensile and flexural moduli, respectively) were obtained with ACA addition. These results indicate that a balance between mechanical properties and weight reduction can be obtained by optimizing the AF and ACA contents, which is interesting to control the cost, performance and appearance of the rotomolded parts.