Executive functions are important for successful accomplishment of walking tasks, particularly during a dual task. Over the past few years, several studies investigated prefrontal cortex activity under different walking conditions in older adults with functional near infrared spectroscopy (fNIRS). However, little is known about changes in dorsolateral prefrontal cortex (DLPFC) activity during walking in the early stages of aging. The main objective of this study was to compare changes in DLPFC activity during simple and dual task walking across three different age groups. Twenty-five young (age range=18-37), twenty-five youngest-old (age range=55-65), and twenty-five older adults (age range=67-87) participated in this study. Main results showed that, during simple task walking, older adults had increased DLPFC activity with equivalent walking performance. This increased mainly concerned the right hemisphere. During dual task walking, older adults had increased right DLPFC activity but seemed to have enough resources to maintain their performance during DT walking. This result supports the idea that compensation mechanisms, due to loss of automaticity of walking in aging, appear already during simple task walking. Measuring cortical activity with fNIRS during a simple task walking might be used as valuable indicator for identifying individuals at risk of falling.