This study reports the synthesis and application of new saponin (SAP)-loaded montmorillonite-human serum albumin (Mt-HSA) nanocomposites (NCs) as an anticancer drug delivery agent. When the biodegradable and biofriendly HSA was combined with Mt., which possesses excellent mucoadhesive properties, the resulting NCs could pass through the gastrointestinal barrier easily. SAP-Mt-HSA NCs were prepared by a modified desolvation technique in which ethanol and glutaraldehyde (GA) were used as precipitating and crosslinking agents, respectively. The efficacy of these NCs was assessed in a colorectal cancer cell line (DLD-1) as an in-vitro gastrointestinal model and L929 fibroblast cells as a healthy cell model. The release profile of SAP and the cytotoxic effect and cellular uptake of NCs were evaluated. The results clearly demonstrated that SAP-Mt-HSA NCs can induce dose-dependent cancer cell death with little or no toxicity toward healthy cells.