Background: Diadochokinetic rates tasks are frequently used for the assessment of diadochokinesia (DKK) in young and elderly adults. However, there is scarce research on healthy elderly adults over 65 years old, and little is known about the effect of different types of stimuli (non-words/real words) in this specific population. Furthermore, the current research supports significant language variations, highlighting the need for language-specific norms. Aims: To investigate the effect of age, gender and type of stimuli (non-words versus real words) in DDK rates in healthy elderly adults of over 65 years of age, and to provide normative data for the Greek language. Methods & Procedures: The participants were 791 healthy monolingual Greek-speaking adults (531 adults, aged 20-39 years; 157 participants aged 65-74 years; and 103 participants aged over 75 years). All participants were monolingual speakers of Greek and had normal hearing acuity, which allowed them to understand and follow instructions. Participants with a medical condition, which would affect DDK rates' performance, were excluded from the study. The time-by-count method was used, and all participants had to repeat as accurately and fast as possible: (1) four disyllabic non-words (/'gaba/, /'taka/, /'kata/, /'baga/); (2) four disyllabic real words (/'kapa/, /'tapa/, /ka'la/, /'paka/); and (3) two trisyllabic non-words (/'pataka/, /'badaga/). All responses were recorded and the speech samples that did not include at least 5 s of correct repetitions were excluded from the analysis. Outcomes & Results: Age affected DDK rates significantly, with older adults achieving slower DDK rates for all speech stimuli (non-words/real words). Gender did not have an effect on the performance of DDK rates. The type of speech stimuli affected DDK rates significantly for all age groups. Analytically, trisyllabic non-word stimuli were articulated more slowly than disyllabic non-word stimuli, and real words were produced faster than non-words. A linear regression analysis revealed that only the repetition of non-words predicted 68.4% of the performance on the repetition of trisyllabic non-words. Conclusions & Implications: The above results complement prior research, which supports that real word stimuli yield faster performance than non-word stimuli. Clinicians should keep in mind that age, language and type of stimuli (non-words/real words) affect significantly the performance of DDK rates, as well as the fact that different types of stimuli tap distinct underlying levels of speech. The current research highlights the need for language-specific norms for different populations.