Abstract. An integer is said to be y-friable if its greatest prime factor P (n) is less than y. In this paper, we study numbers of the shape n − 1 when P (n) ≤ y and n ≤ x. One expects that, statistically, their multiplicative behaviour resembles that of all integers less than x. Extending a result of Basquin [1], we estimate the mean value over shifted friable numbers of certain arithmetic functions when (log x) c ≤ y for some positive c, showing a change in behaviour according to whether log y/ log log x tends to infinity or not. In the same range in (x, y), we prove an Erdös-Kac-type theorem for shifted friable numbers, improving a result of Fouvry & Tenenbaum [4]. The results presented here are obtained using recent work of Harper [6] on the statistical distribution of friable numbers in arithmetic progressions.