Three types of nanoparticles, quantum dots (QDs), gold particles (GPs), and latex particles (LPs), were compared as labels for immunochromatographic assay. The influence of the nature of the label on the analytical performance of the test systems was studied using the example of detection of the antibiotic chloramphenicol (CAP). The limits of detection of CAP are 0.1 ng/mL for QDs, 2.4 ng/mL for GPs, and 0.3 ng/mL for LPs. The unique structure and physical properties of the QD fluorescent labels ensure their competitive advantage over colorimetric labels. The proposed methodology is applicable to determination of characteristics of other nanodisperse labels.