<b><i>Background:</i></b> There is evidence for specific age-related deficits in tasks of verbal fluency. <b><i>Objective:</i></b> The aim of the present study was to evaluate training and transfer effects after 3 weeks of telephone-based verbal fluency training in old age. <b><i>Methods:</i></b> Participants were assigned to one of three training groups, an active control group, or a no-contact control group. Training consisted of 15 sessions of 6 min each over a period of 3 weeks. For the training tasks, different versions of the verbal fluency task were used, each targeting a specific underlying cognitive process (i.e., processing speed, shifting, or inhibition). To measure transfer effects, a neuropsychological test battery including Digit Symbol Substitution, Trail Making, Go/No-Go, Digit Span, N-Back, and a verbal learning and memory test was administered before and after training. <b><i>Results:</i></b> Our findings revealed training gains for initial letter fluency training and phonemic switching training, but not for excluded letter fluency training. Moreover, after initial letter fluency training and phonemic switching training, transfer to other verbal fluency tasks was found. In addition, phonemic switching training led to improvement in an untrained short-term memory task. <b><i>Conclusion:</i></b> The findings demonstrate that a telephone-based cognitive intervention of overall 90 min significantly improved cognitive performance in healthy older adults above and beyond the improvements in the active control group. The findings provide the basis for cognitive interventions that could easily be integrated into everyday lifestyles and are still targeting specific cognitive functions.