In this paper we review the cell-poking technique as an approach for investigating the mechanical properties of living cells. We first summarize the rationale for the technique and the mainly qualitative results obtained so far. Then we provide a technical description of the instrument as it is configured at present. This is followed by a discussion of the current status of analytical results available for interpreting cell-poking measurements. In the final section we apply these results to an analysis of unmodulated and modulated lymphocytes and neutrophils, and conclude that the mechanical response of these leukocytes to indentation is not consistent with simple models developed by previous investigators on the basis of micropipette-aspiration experiments.