For improved cost-effectiveness and temperature-stability, a ready to use lateral flow assay (LFA) is developed in this work for detecting inflammation/infection biomarker C-reactive protein (CRP) in human patient samples on the basis of aptamers. In prescreening investigations, an aptamer with CRP affinity was immobilized on microarray chips in forward and sandwich formats to optimize assay conditions. We suggest these microarray techniques as a resource-sparing and fast-screening instrument for evaluation of various conditions. The capability of the aptamer to detect CRP was shown. Optimized assay conditions were consequently transferred to the LFA-platform. Here we could demonstrate for the first time an aptamer-based LFA for the detection of CRP in human patient samples in pathologically relevant concentrations. The cutoff for CRP detection is set at 10 mg/L, providing a distinctive “yes” (≥10 mg/L CRP) or “no” (<10 mg/L CRP) answer for the patient. The resulting aptamer-based LFA is promising with regard to its application as point-of-care testing (POCT) for efficient monitoring, especially of patients affected by frequent infections or inflammations.