Despite an increase in interest pertaining to the benefits of yoga practice, research focusing on the relationship between yoga practice and attention is limited. This study employed a quasi-experimental pre-test, post-test design to measure whether physical activity had an immediate effect on selective attention and mental concentration in young adults, aged 18 to 25. More specifically, this study compared yoga and aerobic exercise classes to assess whether yoga practice improved attention beyond aerobic activity. The yoga and aerobic groups completed two surveys and the d2 Test of Attention at two observation points: immediately prior to and immediately following participation in their respective classes. An analysis of variance (ANOVA) found a statistically significant improvement between pre- and post-test scores on attention for both groups, with a greater improvement for the aerobic group. The findings show that physical activity had an immediate effect on the attention of the sample.