Polyaniline (PANI)–PbTiO3 composites were prepared by using different inorganic and organic acids by in situ polymerization technique using sodium dodecyl benzene sulfonic acid as a surfactant. The structural analysis was studied by using x-ray diffraction, and it was found that PANI is amorphous in nature. The scanning electron microscopy studies reveal that they are agglomerated and irregular, and size of these grains increase by increasing the amount of PANI with different organic and inorganic acids. The real part of complex permittivity (εʹ) and imaginary part of complex permittivity (εʹʹ) and the real part of the permeability (μ′) are studied at X-band frequency where (εʹ) and (εʹʹ) decreas with increase in frequencies, whereas μ′ increases with increase in X-band frequency and exhibits a maximum value of 0.87 at the resonance frequency of 9–11 GHz of 30 wt% PbTiO3 in PANI matrix. Reflection loss peak of 30 wt% of PANI–PbTiO3 composites is 28.6 dB at 10.8 GHz, which may be attributed to the maximum reflection of the microwave power for the particular doping concentration.