This study attempted to discriminate three types of lung disease pair-wise, namely lobar pneumonia (PNEU), pulmonary tuberculosis (PTB) and lung cancer (LC) using chest radiograph. A modified principal component method applied to wavelet texture measures yielded feature vectors for the pair-wise statistical discrimination procedure. The combination of mean of energy and maximum value texture measures gave good pairwise discrimination rate and classification rate for PNEU-PTB, PNEU-LC and PTB-LC. The result if this study is very promising and further work are needed for verification and validation study with larger sample size.