Background: In recent years nano-sized dendrimer/hyperbranched polymers gained importance in drug delivery applications. Objective: In this study, a novel fatty acid-based hyperbranched resin (HBR) was synthesized and used for tamoxifen (TAM) and idarubicin (IDA) delivery. Methods: The core of the HBR was dipentaerythritol, and the branching was provided by dimethylolpropionic acid. The molecule was terminated by ricinoleic acid. Chemical and structural characterization of the resin was carried out and then drug-loading experiments were performed. Conclusion: The loading efficiencies were found to be 73.3% for TAM and 74% for IDA. The Fourier transform infrared spectroscopy analysis showed that TAM physically bounded onto the resin whereas IDA interacted chemically. Controlled release in phosphate buffer was improved by Pseudomonas sp. lipase and sodium dodecyl sulfate. The release rates decreased with the increase of loading concentrations. The cytotoxicity analyses were carried out on MCF-7 breast cancer cells for both drug-free and drug-loaded HBR. Drug-free particles did not have significant toxicity. Drug-loaded nanoparticles caused higher levels of cell death than pure drugs.