We report the first observation of B0s→ψ(2S)ϕ decay in pp¯ collisions at s√=1.96  TeV using 360  pb−1 of data collected by the CDF II detector at the Fermilab Tevatron. We observe 20.2±5.0 and 12.3±4.1 B0s→ψ(2S)ϕ candidates, in ψ(2S)→μ+μ− and ψ(2S)→J/ψπ+π− decay modes, respectively. We present a measurement of the relative branching fraction B(B0s→ψ(2S)ϕ)/B(B0s→J/ψϕ)=0.52±0.13(stat)±0.04(syst)±0.06(BR) using the ψ(2S)→μ+μ− decay mode.