This paper presents a simple, low-cost, and novel technique for measuring the temporal pulse shape of a nanosecond laser pulse accurately and consistently. The measurement configuration consists of a focusing lens, a tapered rod, and a digital noise filter. Using this setup, the pulsewidth of a nitrogen laser has been determined experimentally. Compared with an unaided measurement configuration, the new setup reduces the maximum deviation from 24.5% to 6.2% and the standard deviation from 7.6% to 1.4%, respectively.