Impulsive differential equations are a useful tool for assessing timeliness of regular interventions, but the question of stochasticity in the timing and nature of the impulses has not been investigated. We use a previously published model of malaria as a baseline to investigate varying three key parameters: the time of the impulse, the duration between impulses and the degree of effectiveness of the impulse. Surprisingly, the model remains impervious to most biologically reasonable variations. However, we also showed that some extreme theoretical possibilities—such as very small durations or impulses that go backwards in time—can lead to unexpected outcomes. The malaria model can withstand large stochastic variations in the impulse parameters, suggesting that impulsive differential equations are fairly robust, at least when the virulence of the disease is high.