The authors present the basic analytical values for, and the calculation of CORESTA efficiency indices Ei related to some chemical items (phenols, polyphenols, Ehrlich-positive compounds, hetero-N compounds, indole) in the smoke of filter cigarettes (dark air cured type, two types of filter tips of the acetate group, with and without activated carbon additive). The calculation presented for proposed "selectivity indices" Ei / EG confirms factually the high grade of selectivity for phenols and some hetero-N compounds in the experimented systems; some critical facts are called to the attention concerning the role played by the activated carbon additive