There is increasing recognition that neurotrophin (NT) signaling occurs in non-neuronal tissues including airway smooth muscle (ASM). We recently demonstrated that NTs such as brain-derived neurotrophic factor (BDNF) enhance intracellular Ca²⁺ ([Ca²⁺]_i) and force regulation in human ASM. Increased NT expression has been observed in airway diseases such as asthma and allergy. In the present study, we tested the hypothesis that NTs contribute to inflammation-induced enhancement of ASM contractility. Using human ASM cells and real-time fluorescence [Ca²⁺]_i imaging, we examined the contribution of the high-affinity TrkB and low-affinity, pan-NT p75NTR receptors to [Ca²⁺]_i regulation under control conditions and following exposure to the pro-inflammatory cytokine tumor necrosis factor alpha (TNF; 20ng/ml). Exposure to TNF substantially increased both TrkB and p75NTR expression, and enhanced [Ca²⁺]_i responses to agonist (ACh, histamine). Exposure to 10 nM BDNF for even 30 min substantially and synergistically enhanced TNF effects on [Ca²⁺]_i responses to agonist. Small interfering RNA (siRNA) suppression of TrkB substantially blunted the effect of BDNF on [Ca²⁺]_i responses to agonist (with greater effect on Ca²⁺ influx via store-operated Ca²⁺ entry compared to sarcoplasmic reticulum Ca²⁺ release) in both control and TNF-exposed cells. However, p75NTR suppression by siRNA had no significant effect on [Ca²⁺]_i responses in either cell group. These novel data demonstrate that NTs influence ASM contractility, and suggest a potential role for neurotrophins in airway diseases.