OBJECTIVES: Patients with cancer who use complementary and alternative medicines (CAMs) in conjunction with chemotherapy treatment are at risk of manifesting anticancer drug-CAM interactions (DCIs), which may lead to negative therapeutic outcomes. This article describes a novel iPhone application developed for the Mobile Internet, called OncoRx-MI, which identifies DCIs of single-agent and multiple-agent chemotherapy regimen (CReg) prescriptions. METHODS: Drug-, CAM-, and DCI-related information was compiled from various hardcopy and softcopy sources, and published literature from PubMed. Overall management plans for the CRegs were then developed. The iPhone Web documents were constructed using Adobe software and programming scripts, and mounted onto a third-party server. DCI searches are based on CReg acronyms, and OncoRx-MI is designed to fit the iPhone screen configuration for improved usability. A small usability study was also carried out and the user feedback presented. RESULTS: OncoRx-MI is able to detect over 2700 interactions between 256 CRegs and 166 CAMs, making up a total of over 4400 DCI pairs. The CAMs are classified into seven categories based on their uses in supportive care, and non-cancer-related CAMs are also included. The majority of the DCIs are pharmacokinetic in nature (79%), involving the induction and inhibition of the cytochrome P450 isozymes and p-glycoprotein. Pharmacodynamic DCIs include hepatotoxicity (39%), altered corticosteroid efficacies (30%), and increased risks of hypoglycemia (4%), hypertensive crisis (2%), bleeding, and serotonin syndrome (1% each). CONCLUSIONS: OncoRx-MI is the first mobile application of its kind that allows searching of DCIs for CRegs through 3G networks, and is intended to improve pharmaceutical care of patients with cancer by assisting health care practitioners in managing CReg interactions in their clinical practices.