The radiative lifetime of 14 levels in the z5F, z5D, and z5G terms of Co II have been measured with use of time-resolved laser fluorescence spectroscopy with a Co+-ion beam. Our lifetime values are shorter by 15-50 % than earlier results from beam-foil time-of-flight measurements. The life­times were converted to 41 individual transition probabilities with use of branching ratios measured on spectra recorded with the 1-m Fourier-transform spectrometer at the Kitt Peak National Obser­vatory. On average our transition probabilities agree with those of Kurucz and Peytremann; for AS =1 transitions their calculated values are lower than our experimental results by a factor of  1/4.