<p>This work aims to investigate the performance of composites based on polylactic acid reinforced with snail shell particles using 3D printing technology. Snail shells were transformed into micron size particles by following three steps: shell segregation, oven drying, and ball milling. Snail shell powders were combined with polylactic acid in varying concentrations of 5%, 10%, 15%, and 20% (by weight). A custom-built filament extruder created the composite filaments suited for fused deposition modeling. The composite samples were then manufactured using 3D printing technology. The impact of adding snail shell powders on the composites’ mechanical and morphological characteristics was investigated. Mechanical tests were performed on the produced composites to measure the tensile, flexural, and compressive strength. Scanning electron microscopy was used to examine the composites’ morphological characteristics. The tensile and compressive strength of the composites increased by 10.6% and 11.1%, respectively, when the weight percentage of snail shell powders was increased to 15 wt%, according to the results. The mechanical performance of the composites indicates that snail shell powders could be an excellent reinforcing material. Morphological investigation revealed that the snail shell powders were distributed uniformly in polylactic acid on increasing its content to 15 wt% and then agglomerated at 20 wt%. </p> Graphical abstract <p></p>