Abstract. We will present the discovery of Quasi Periodic Oscillations (QPOs) in several transient high magnetic field accretion powered pulsars using RXTE/PCA observations of few sources during their outbursts. Remarkably, in two of these sources, the QPOs have been detected only in a few observations near the end of the outbursts when the source intensity had decayed by more than two orders of magnitude from the peak of the outbursts. The QPO features are found to have significant energy and intensity dependence. These low frequency QPOs have so far been observed in 21 high magnetic field pulsars, a number comparable to or larger than any other class of X-ray sources. We investigate if the measurements of the QPO frequency and X-ray luminosity can be used to estimate the magnetic field strength reliably.