In vascular smooth muscle, it has been described that testosterone (TES) produces relaxation by blocking L-type Ca²⁺ channels. Recently, we found that L-type Ca²⁺ and store-operated Ca²⁺ (SOC) channels are the main membranal structures that provide extracellular Ca²⁺ for carbachol (CCh)-induced contraction in airway smooth muscle (ASM). We studied the possible interactions between L-type and SOC channels in TES-induced relaxation in guinea pig ASM. TES (10, 32, 100, and 178 μM) induced a complete relaxation of CCh-precontracted tracheal smooth muscle, and indomethacin partially inhibited this response. In single myocytes, the KCl-induced intracellular Ca²⁺ increase ([Ca²⁺]_i) was decreased by 32 and completely blocked by 100 nM TES. This androgen (32 and 100 μM) significantly diminished (~25 and 49 %, respectively) the capacitative Ca²⁺ entry. Myocytes stimulated with CCh produced a transient Ca²⁺ peak followed by a sustained plateau. D-600 was added during the plateau phase, and a partial diminution (~35 %) was observed. A greater decrease (~78 %) was seen when 2-aminoethyl diphenylborinate (2-APB, SOC antagonist) was used. The combination of both drugs completely abolished the Ca²⁺ plateau induced by CCh. TES (100 μM) also completely abolished the CCh-induced Ca²⁺ plateau. Indomethacin significantly diminished this effect of TES. PGE₂ and butaprost proportionally decreased the Ca²⁺ plateau as indomethacin blocked it. Sarcoplasmic reticulum refilling was partially, dependently, and significantly diminished by TES. We concluded that TES-induced relaxation involves blockade of L-type Ca²⁺ channels at nanomolar and SOC channels at micromolar concentration and PGE₂ seems to be also involved in this phenomenon.