Chloropyridines are industrially important compounds. Some physico-chemical properties,. viz., vapour pressures, heats of vaporization (Delta H-v), activityivity coefficients (gamma(infinity)) and excess partial molar thermodynamic quantities of chloropyridine isomers are determined in the present investigations using purpose built gas liquid chromatographic (GLC) instrument. These properties are evaluated on two conventional stationary phases of varying polarity, i.e., OV-17 and diethylene glycol adipate (DEGA). The stationary phase-probe interactions are discussed in the light of the results obtained.