The present revision of the nuclear structure properties for the nuclides belonging to the A = 178 mass chain contains many improvements and additions to the material presented in the previous evaluation (1994Br18, Nucl. Data Sheets 72, 221 (1994)). Besides updating many values, and including supplementary data for already known levels, transitions and level schemes, the most noteworthy modifications with respect to the prior evaluation are extensive additions to the level schemes of 178 Yb, 178 Hf, 178 Ta, 178 W. 178 Ir, 178 Pt and 178 Hg, based on HI reaction works performed after the last cutoff date (July 1993), and to 178 Hf due to new data from recent Coulomb excitation experiments. Light ion ( 3 He, α) beam experiments have added many data for 178 Ta. Beta decay studies have also provided significant data for 178 W and 178 Pt. Lastly the first report of the identification of 178 Tl and 178 Pb is included.