For a graph G and p ∈ [0, 1], let Gp arise from G by deleting every edge mutually independently with probability 1 − p. The random graph model (Kn)p is certainly the most investigated random graph model and also known as the G(n, p)-model. We show that several results concerning the length of the longest path/cycle naturally translate to Gp if G is an arbitrary graph of minimum degree at least n − 1.For a constant c, we show that asymptotically almost surely the length of the longest path is at least (1−(1+ǫ(c))ce −c )n for some function ǫ(c) → 0 as c → ∞, and the length of the longest cycle is a least (1 − O(c − 1 5 ))n. The first result is asymptotically best-possible. This extents several known results on the length of the longest path/cycle of a random graph in the G(n, p)-model.