Background: Magnetic fields in human environment can affect on learning and memory. This study was conducted on evaluation the effect of short time exposure to 2 and 8 MT magnetic fields on rat consolidation of spatial memory. Materials and Methods: Thirty-six male Wistar rats (3-4 month old, 235 ±15 g) were randomly allocated in three groups (sham and exposed to 2 and 8 MT magnetic fields). Animals were given 8 trials (one training session) at 2 blocks, with 3 minutes interval between the blocks for one day in Morris Water Maze. Immediately after training, head exposure was performed by a 50 Hz, 2 or 8 MT magnetic fields for 20 minutes. Forty eight hours after training and exposure to magnetic field, animals were given a 60 seconds probe trial.Results: Animals exposed to 8 MT but not to 2 MT magnetic fields spend significantly less time in the platform quadrant during 60 seconds probe trial and had different swimming patterns so that they showed fewer tendencies for finding the platform. Conclusion: The results of this study showed that short time exposure to 50 Hz, 8 MT but not 2 MT magnetic fields can impair consolidation phase of spatial memory