The aim of this research was the translation, cultural adaptation, and psychometric validity of the WHOQOL-OLD and OPQOL-35 questionnaires. The WHOQOL-OLD and OPQOL-35 questionnaires in their original version are considered appropriate for measuring these factors and aim to demonstrate a reliable measure of quality of life. For their utilization and the expansion of their accessibility by the Greek population, with the ultimate goal of locating and intervening in cases of vulnerability, in the first stage, the forward translation, the reconciliation report, and the backward translation were performed. Then, the translated Greek version was applied in a pilot study. The total sample of the research consisted of 300 people of the population of interest (elderly Greek), of whom 50 participated in the successful pilot research. The majority of the sample lives in the Prefecture of Trikala and identifies with the female sex. The mean age of the individuals who participated in the study anonymously was 72.1 years. SPSS 22.0 and AMOS programs were used for data analysis. In conclusion, the Greek version of the WHOQOL-OLD and OPQOL-35 questionnaires proved to be reliable and valid. The adapted questionnaires are considered equally capable of being used comparatively for intercultural research, as well as for the timely detection of vulnerability of the elderly for immediate intervention, provided that the Greek version proves reliability and validity.