An apparatus for a polymerase chain reaction (PCR) diagnosis includes a transmitter that includes a multi-wavelength light source outputting a first light source signal and a second light source signal, which have different wavelengths, and that applies the first light source signal and the second light source signal to a DNA sample, a code generator that generates a first code signal and a second code signal corresponding to the first light source signal and the second light source signal, respectively, a delay controller that generates a first delay signal and a second delay signal corresponding to the first code signal and the second code signal, respectively, and a receiver that compares the first and second fluorescent signals emitted from the DNA sample with the first and second delay signals, and accumulatively integrates the first fluorescent signal or the second fluorescent signal based on the comparison result.