Despite the recent campaigns to eliminate smoking and hinder the detrimental effects of passive smoking (PS), actual smoking rates still increase worldwide. Several physiological systems, with the respiratory being the primary, are disrupted by PS and progressively deteriorate through chronic exposures. This is of particular importance in children, given that respiratory complications during childhood can be transferred to adulthood, lead to significantly inferior health profiles. Hence, it is no surprise that children that are exposed to PS either in utero or during their adulthood may have an increased prevalence of allergies and asthma. However, investigating the acute effects of PS in children is inherently limited by complexities pertaining mainly to ethical constrains. Knowledge of the acute effects could be very important as it is the dose-dependant acute effects of passive smoking that lead to the long-term adaptations linked with the development of allergy and asthma. Current available data show that the chemical and carcinogenic constituents of tobacco have profound effects on children's health as they may disrupt normal biological development. PS appears to have pronounced effects on respiratory parameters that promote asthma development and persistent wheezing rather than other allergies. As such, PS exposure has to be eliminated and researchers have to develop interventions for supporting smoking cessation as well as minimised PS exposure either this is in utero or during childhood.