This study examined the effectiveness of a Social Intelligence Intervention (SII) in improving components of social intelligence, and whether neuroticism moderates such associations in 130 participants aged 45-70. We hypothesized that the SII will improve participants' social intelligence across several factors: social awareness, social skills, social information processing, and perspective taking. Furthermore, we examined if neuroticism moderated participants' responsiveness to the intervention. Specifically, we hypothesize that individuals with high levels of neuroticism will have greater improvements in social intelligence. Individuals were randomly assigned to participate in the SII (n=71) or an attention control condition (n=59) that focused on healthy living tips. Individuals provided self-report data prior to participation in the study, and following completion of the intervention or attention control condition. The results were not statistically significant, however there was a trend for social information processing to improve with the SII. Neuroticism and time significantly moderated social awareness. This research suggests that the SII may not be effective in improving social intelligence scores for participants in midlife. Thus, the SII should be enhanced to surpass improvements that could potentially be from common factors in the intervention.