High-precision laser spectroscopy of helium is a powerful tool for testing QED calculations and for an accurate determination of the fine-structure constant &agr;. Here, we report a new measurement of the fine-structure intervals of the23Plevel of helium with an accuracy of kHz. They are measured from the frequency difference between23S1→23PJoptical transitions observed with fluorescence-saturation spectroscopy in an atomic beam, in the absence of magnetic fields. A discussion of the systematic effects in the measurements is given, describing for the first time in helium the shift induced by mechanical effects of the light. Finally, a comparison with previously reported measurements is discussed. ©1999 American Institute of Physics.