The aim of this study was to assess gains related to working memory (WM) training, in the short and long term (9 months after the training), in abilities required in everyday life, and in cognitive measures in old-old adults (aged ≥ 75 years). Thirty-two community-dwelling older adults (aged 75-85 years) were randomly assigned to a training or an active control group. In addition to testing for any specific gains in a WM task similar to the one used in the training (criterion task), we sought transfer effects to: 1) abilities involved in everyday life using objective performance-based tasks (the Everyday Problem Test [EPT] and the Timed Instrumental Activities of Daily Living [TIADL] scale; 2) tasks demanding the comprehension and recall of spatial information and pairing names with faces; and 3) a measure of inhibitory control, that is, recall errors (intrusion errors). Only the trained group showed specific gains in the criterion task, and in the TIADL in the short term. At follow-up, the trained group maintained gains in the criterion task, and showed transfer effects to everyday problem-solving (in the EPT), and in constructing spatial representations of an environment. The trained group also improved in a cognitive inhibition measure (intrusion errors) at follow-up. No such improvements were seen in the active control group. WM training may be a valid way to help old-old adults preserve at least some abilities related to everyday functioning.