While studies on the damaging effects of PM2.5 air pollution are abundant, studies seeking to understand the factors that influence human behaviors for the avoidance of exposure to PM2.5 are lacking. Theory of Planned Behavior (TPB) can be used to investigate the effects of Attitudes (AT), Subjective Norms (SN), and Perceived Behavioral Controls (PBC) in the Behavioral Intentions (BI) of parents with young children against exposure to PM2.5. Questionnaires, based on the TPB used to predict BI, were distributed to 610 parents in Taipei City and New Taipei City. Our results revealed that the AT of both groups had a significant positive predictive effect on their PBC and BI. While the SN of the Taipei group affected BI directly, there was no significant effect on the BI from the SN of the New Taipei group. Using path analysis, Taipei City and New Taipei City groups had different BI paths: All five hypotheses are statistically significant and form four paths in the Taipei City group. While only four hypotheses in the New Taipei City group formed three paths and no path for SN-BI. Both groups formed behaviors that were based on the SN/PBC around them, which ultimately contributed to the BI of their protective behaviors.