Malaria is a global health concern, with over 400,000 deaths annually. Similar to many viruses, a person can be infected with the malaria parasite and not exhibit symptoms. Therefore, in order to eradicate malaria, it is necessary to identify and treat both the symptomatic patients and asymptomatic carriers. We have developed a diagnostic method based on optical differential spectroscopy for performing rapid screening of unprocessed whole blood samples. The portable system has demonstrated the ability to detect clinically relevant concentrations of the malaria biomarker, hemozoin, as well as synthetic hemozoin in initial trials.