This paper presents elastic transactions, an appealing alternative to traditional transactions, in particular to implement search structures in shared memory multicore architectures. Upon conflict detection, an elastic transaction might drop what it did so far within a separate transaction that immediately commits, and resume its computation within a new transaction which might itself be elastic. We present the elastic transaction model and an implementation of it, then we illustrate its simplicity and performance on various concurrent data structures, namely double-ended queue, hash table, linked list, and skip list Elastic transactions outperform classical ones on various workloads, with an improvement of 35% on average. They also exhibit competitive performance compared to lock-based techniques and are much simpler to program with than lock-free alternatives. (C) 2016 Elsevier Inc. All rights reserved.