Background and purpose: Adrenoceptors can associate with cardiac caveolae. To investigate the function of vascular caveolae, adrenoceptor-mediated effects were compared in the saphenous artery of caveolin-1 knockout (cav-1KO) and wild-type (WT) mice. Experimental approach: Electronmicroscopy was used to detect caveolae. Real-Time quantitative PCR was used for adrenoceptor subtypes. Catecholamine-evoked contractions and relaxations were studied in arterial segments. Key results: Caveolae were found in arterial smooth muscle from WT but not from cav-1KO mice. Arterial mRNA levels for the adrenoceptors α _1A, α _1B, α _1D, β ₁, β ₂ and β ₃ were similar in cav-1KO and WT. (-)-Noradrenaline contracted cav-1KO (-log EC ₅₀M=7.1) and WT (-log EC ₅₀M=7.3) arteries through prazosin-sensitive receptors. Maximum (-)-noradrenaline-evoked contractions were greater in cav-1KO than WT arteries. (-)-Isoprenaline relaxed WT arteries (-log EC ₅₀M=7.3) more potently than cav-1KO arteries (-log EC ₅₀M=6.8); the effects were antagonized partially and similarly by the β ₂-selective antagonist ICI118551 (50 nM). The (-)-isoprenaline-evoked relaxation was partially antagonized by the β ₁-adrenoceptor-selective antagonist CGP20712 (300 nM) in WT but not cav-1KO arteries. The β ₃-adrenoceptor-selective antagonist L748337 (100nM) partially antagonized the relaxant effects of (-)-isoprenaline in cav-1KO but not in WT arteries. BRL37344 partially relaxed arteries through β ₃-adrenoceptors in cav-1KO but not WT. The relaxant effects of BRL37344 were decreased by the NO synthase inhibitor ΩL-nitroarginine. Conclusions and implications: The function of arterial α ₁- and β ₂-adrenoceptors is similar in cav-1KO and WT mice. β ₁-adrenoceptor-mediated relaxation in WT is lost in cav-1KO and replaced by the appearance of β ₃-adrenoceptors.