Optimal aging is strongly related to personality factors along with health-behavior habits. Personality has played a key role in understanding the interactions between human behavior and the environment and as a vital predictor in determining health outcomes of individuals. Although previous studies have found links between personality traits and health, less is known about more process-oriented personality constructs, such as goals and self-regulatory strategies as linkages between traits and health outcomes. The purpose of this study is to explore the dynamic linkages of personality and health by examining how daily health-goal progress is associated with daily positive and negative affect as well as whether the association between health-goal progress and positive and negative affect can be predicted by personality traits of neuroticism and conscientiousness. Main research questions are: 1) Are daily positive and negative affect associated with daily health-goal progress? 2) To what extent are the traits of neuroticism and conscientiousness related to the overall levels of daily health-goal progress over a 100-day time period? 3) Do neuroticism and conscientiousness moderate the relationships between daily positive affect and daily health-goal progress as well as between negative affect and daily health-goal progress? This study was guided by developmental systems theory (Ford & Lerner, 1992) and the six-foci model of personality (Hooker & McAdams, 2003). This study utilized data from the "Personal Understanding of Life and Social Experiences" (PULSE) project that was a 100 day internet-based, daily study of Oregon residents over the age of 50. The sample for this study (N = 76) included participants who have participated at both baseline (initial survey) and the microlongitudinal phase (over 100 days). Personal health goals, neuroticism, and conscientiousness were measured at baseline. Daily health-goal progress, daily positive affect, and negative affect were measured over 100 days. Multilevel modeling analysis was used to examine within-person variations and between-person differences in daily health-goal progress and daily positive and negative affect by estimating an intercept (initial status) and slope (change) for each individual. The results of this study show that first, daily health-goal progress was positively coupled with daily positive affect and negatively coupled with daily negative affect within persons. Second, the associations between daily positive affect and daily health-goal progress and between daily negative affect and daily health-goal progress varied between individuals. Third, health-goal progress on the previous day was positively related to concurrent positive affect and negatively related to concurrent negative affect. Fourth, individuals high in neuroticism and individuals high in conscientiousness were only marginally likely to experience higher levels of health-goal progress over the 100-day period compared to those with low scores. Fifth, individuals high in neuroticism when experiencing high levels of negative affect tended to report lower levels of daily health-goal progress. These findings may provide enhanced knowledge of patterns of day-to-day variability within persons and lead to better health care. Moreover, the findings of the current study suggest that health-improving interventions could be targeted individually to participants based on knowledge of the linkages between daily goal progress and daily affect and personality traits. Ultimately, the personality of older adults may act as risk factors and/or protective factors in the processes of aging during the second half of life. / Graduation date: 2013