Background and AimsAsthma is a chronic inflammatory pulmonary disease which affects 10%–20% of children and adolescents. Inhaled corticosteroids (ICS) is one of its most effective therapies. The effect of systemic corticosteroids on decreasing bone mineral density (BMD) was investigated and proved in children; however, the influence of ICSs on bone density has still remained unclear. This study evaluates the bone mineral density of children and adolescents with asthma in southern Iran and the associated factors, for example, amount of used inhaled steroid.MethodThis case‐control study enrolled 41 children and adolescents (aged 8–18 years) with asthma and their age and gender‐matched controls in 2019–2020. Serum Calcium, phosphate, vitamin D, and bone mineral density were measured. Their physical activity, sun exposure, and fracture history were evaluated subjectively.ResultsLumbar BMD and BMD Z‐score in patients showed no significant difference with controls (p = 0.23, p = 0.73). Also, it showed that there was no significant difference in biochemical studies, growth, and bone densitometry parameters between patients who used ICSs for less than 3 months/year corticosteroid therapy compared to those with equal or more than 3 months/year usage. Prevalence of vitamin D deficiency was 28% and 8% in the controls and patients, respectively (p = 0.005).ConclusionThe present study showed that 9.46% of children and adolescents with asthma had low bone mass for chronological age, and it is not significantly higher than normal population. Dosage of inhaled steroid did not associate with osteoporosis in these patients. Prevalence of vitamin D deficiency in patients was lower than normal population, probably due to receiving vitamin D in their routine follow‐ups.