Objective: To assess whether cognitive reappraisal and acceptance are effective emotion regulation strategies to decrease the influence of negative affect on intention to accept maternal pertussis vaccination (MPV) among pregnant women in the Netherlands. Methods: An experimental study with baseline and two follow-up measurements was conducted. Participants selected after baseline (N = 382) were randomized into two experimental groups (cognitive reappraisal, acceptance) and a control group. The effect of the experimental manipulations on negative affect was examined with multilevel analyses. A moderation analysis was performed to examine whether the manipulations moderated the association between negative affect and intention. Results: All groups showed a decrease in negative affect (all p's < 0.001), with no differences between groups. A small decrease in the influence of negative affect on intention was found among those who used acceptance. Conclusion: No additional value of the emotion regulation strategies was found compared to the control group. However, exploratory analyses showed that acceptance seemed a promising strategy to decrease the influence of negative affect on intention to accept MPV. Practice implications: This study stressed the relevance for communication strategies to consider the emotions pregnant women experience during the decision-making process about the MPV.