Purpose: To investigate the prevalence and severity of dental caries in children with a history of asthma in addition to their salivary characteristics, flow rate and buffering capacity, as well as the salivary level of Mutans streptococci (MS) and lactobacilli present. Materials and Methods: The study sample was composed of 30 cases and 30 controls with an age range from 5 to 13 years. The cases involved children with a past history of asthma, while the controls were medically fit children. The study was conducted from 2010 to 2011 and patients were randomly selected through the electronic filing system at King Abdul-Aziz University Hospital (R4 system), Jeddah, Saudi Arabia. Interviews and questionnaires were completed by the parents of the children involved and dental examinations were performed. Stimulated salivary samples were collected to determine the salivary flow rate, buffering capacity and salivary levels of MS and lactobacilli. Results: No significant differences were found in the DMFT, dmft scores or community periodontal index (CPI) scores between the cases and controls. However, there was a positive correlation between DMFT and dmft scores (r = 0.83, P 0.0001) in both the cases and controls. In asthmatic patients who took their medication 3 times a day or more, the level of MS and lactobacilli was significantly higher (P = 0.014 and P = 0.008, respectively) compared with other asthmatic patients. Patients with severe asthma had significantly lower salivary flow rate levels than other asthmatic patients (P = 0.040), while patients taking a combination therapy of anti-asthmatic drugs with corticosteroids had higher levels of lactobacilli compared with patients using other medications (P = 0.02). Conclusions: The frequency of taking asthma medication, the severity of asthma and the use of combination therapy can significantly alter the salivary characteristics in asthmatic children. Keywords: asthma, caries, children, saliva