A pneumoperitoneal needle (1) is described which comprises a hollow needle (2) for penetrating a body cavity and a hollow obturator (3) having a blunt tip (30) and through which a fluid may be transferred to and from the body cavity. The obturator (3) is mounted within the needle (2) and is linearly movable between a first position in which the blunt tip (30) of the obturator (3) extends beyond the tip (40) of the needle (2) and a second position in which the tip (40) of the needle (2) extends beyond the tip (30) of the obturator (3). There is also biassing means (7) which biasses the obturator (3) to the first position and the biassing means (7) is such that during penetration of the body cavity the resistance is sufficient to overcome the biassing means (7) and move the obturator (3) from the first position to the second position. After the body cavity has been penetrated the obturator (3) returns to the first position under the action of the biasing means (7). The obturator (3) is rotatable within the needle (2) and has through its wall at least two apertures (31, 32) adjacent to the tip (30) of the obturator (3) so that when the obturator (3) is in the first position fluid may pass through at least one of the apertures (31, 32) irrespective of the orientation of the obturator (3) relative to the needle (2). There is also a visual indicating means (5, 6) which indicates whether or not the obturator (3) is in the first position.