The extensive research done on the interrelationship between different social factors such as social class, gender and age and different linguistic variables has shown that these factors have important effects on the way language is used. Among these factors a special importance can be placed on age due to the role it plays in revealing different patterns of language use, such as the age-grading pattern, the normal pattern of age differentiation and the important patterns of language change which can inform us about the emergence of a linguistic form or the death of some old form. This paper is intended to examine the interrelationship between age and the usage of Shirazi vocabulary or lexical items. Sixty respondents belonging to 6 age groups of Shirazi speakers answered a 60-item questionnaire. Each item included one Shirazi word with its definition and sometimes a short example to clarify its meaning. The respondents had to choose between two choices: either they used the item or they did not. The analysis of the results showed that age was an influencing factor on the speech of the speakers as the older people had a large collection of active Shirazi words (they actively used all the words) while the younger generation had two collections of more active and less active Shirazi words and as the age of the subjects increased their mean scores which represented their usage of Shirazi vocabulary items also increased. These words were also used less among the more educated Shirazi speakers.