The aims of the present study are formulated to test theoretical assumptions of the incivility spiral presented by Andersson and Pearson (1999). The first aim is to investigate possible longitudinal outcomes of witnessed workplace incivility, in the form of instigated incivility and well-being. An additional aim is to explore whether witnessed workplace incivility is indirectly related to instigated incivility or well-being over time, via lower levels of perceived organizational justice. Lastly, we aim to explore if control, social support (from coworkers and supervisors), and job embeddedness moderate the relationship between witnessed and instigated incivility over time. An online questionnaire was distributed to a panel of Swedish engineers at three time points over one year with about six months between waves. Longitudinal data were provided by 341 respondents. Results from longitudinal structural equation panel models showed that witnessed workplace incivility, over time, predicted subsequent higher levels of instigated incivility but not lower levels of well-being. In addition, witnessed incivility predicted lower levels of perceived organizational justice over time but perceived organizational justice did not mediate the relationship between witnessed and instigated incivility or well-being. Finally, the results showed that control, social support from supervisors (but not coworkers), and job embeddedness partly moderated the relationship between witnessed and instigated incivility over time. The relationship between witnessed and instigated incivility between time 1 and time 2 was stronger when levels of control, support and job embeddedness were high. However, job embeddedness was the only robust moderator of the relationship.