Hyperfine-structure (hfs) measurements of the 592-nm $5d{[\frac{7}{2}]}_{4}^{o}\ensuremath{-}6p{[\frac{5}{2}]}_{3}$, the 612-nm $5d{[\frac{3}{2}]}_{2}^{o}\ensuremath{-}6p{[\frac{5}{2}]}_{3}$, and the 581-nm $5d{[\frac{3}{2}]}_{2}^{o}\ensuremath{-}6p{[\frac{3}{2}]}_{1}$ transitions in Cs II are performed with the beam-laser technique. The hyperfine coupling constants $A$ and $B$ are evaluated from the experimental data. A comparison with semiempirical calculations of the hfs constants is made. Radiative lifetimes of the levels $6p{[\frac{5}{2}]}_{3}$, $6p{[\frac{3}{2}]}_{2}$, and $6p{[\frac{3}{2}]}_{1}$ are measured with the cascade-free beam-laser technique. The measured lifetimes are compared with lifetimes obtained from semiempirical calculations using the Coulomb approximation.