The main objectives of this study were 1) to examine changes in self-reported moods and emotional states from before to after Iyengar Yoga classes and how they are affected by the practice of different types of Yoga poses and (2) to determine whether observed changes in mood depend on one’s personality traits. The participants were 11 healthy Yoga students in a nine-session Yoga course in which three different types of Yoga poses were compared: back bends, forward bends, and standing poses. Each 90-minute class focused on one of the three types of poses with three repetitions of each type of class. Self-ratings of 15 moods dealing with positive, negative, and energy-related emotional states were obtained before and after each class. Personality traits of depression, anxiety, and hostility were assessed at an initial orientation. Independently of the specific pose, positive moods increased, negative moods decreased, and energy-related moods increased from before to after classes with most changes lasting for two hours. Specific poses resulted in differences in how moods were affected, with back bends associated with greater increases in positive moods. Some mood changes were dependent on one’s characteristic personality traits. The positive mood effects of back bends were greater for participants who were relatively hostile or depressed. The specific and nonspecific effects of different bodily postures and movements on psychological processes in Yoga and other forms of physical activity deserve further study. Yoga practices should be investigated for their potential clinical application in mood disorders and depression.