We report observations of a 7 &mgr;m diameter, 20 mm long carbon fibre Z‐pinch driven by a pulsed power generator delivering 85–100 kA with a 50 ns (10–90 &percent;) rise time. Time integrated soft x‐ray pinhole camera images show that the emission is from a series of bright spots distributed non‐uniformly along the pinch. The spots are about 100 &mgr;m in size and at a temperature of about 100 eV. The tenuous plasma between the spots is at higher temperatures of about 150 eV. x‐ray streak photography shows that bright spots do not emit simultaneously or in any particular spatial sequence. The first bright spot emits usually at about 30 ns. Each spot emits for a time less than 1 ns. Harder x‐rays are emitted from the anode. In all cases the bright spot emission is seen to occur only during the harder x‐ray pulse. Two pulses are seen. The first of 20 ns duration is observed at current initiation and the second 30–100 ns long occurs later at about 20–25 ns. Analysis of the x‐ray emission from the anode shows that the first pulses is consistent with a 150 keV, 3 kA electron beam and the second pulse with a beam of about 20 keV, 20 kA. The bright spots are also seen in optical streak photographs. The emission is also transient ‐ the duration of the brightest emission is of the order of 1 ns ‐ and the bright spots move axially. They sometimes bifurcate, occasionally combine. Observations with a 7 ns ruby laser show that the fibre pinch expands radially with a velocity>2.5 104 ms−1. Islands of high density form at about 8 ns. These islands are spatially coincident with the x‐ray bright spots and persist for a longer time (30 ns to 50 ns). The radial acceleration of the pinch becomes inward at 8 ns, suggesting that Rayleigh‐Taylor instability may be responsible for the instability.