Nuclear magnetic resonance pulse techniques are applied in situ to investigate the dynamics of mobile dislocations during creep deformation of NaCl single crystals. 23Na spin‐lattice relaxation rates were measured in the rotating frame (T1ρ) during compression creep of single crystals of NaCl along the  direction at 478 K and 20 MPa. The relaxation rates are evaluated from the spin‐echo height following a π/2 locking and 64° pulse sequence. The mean jump distance of the mobile dislocations, evaluated from the ratio of the signal heights without deformation and during creep, decreased with time/strain reaching a constant value at the onset of the steady‐state creep regime. The results are compared with the dislocation‐dislocation spacing, the subgrain size, and the jump distance predicted from creep models.