By means of published data on the concentration of 7Be in the troposphere between 30¿ and 75¿N, together with concentrations measured over the Netherlands, the tropospheric content of 7Be has been estimated. Comparison of this value with published rates of deposition of 7Be in the same latitude band shows that the mean tropospheric residence time of this nuclide is probably not less than 22 days and is more likely of the order of 35 days. This is in agreement with previous estimates and not in agreement with the value of 1 week or less proposed recently by Martell and Moore.