We examined basic auditory temporal processing in children with language-based learning problems (LPs) applying magnetencephalography. Auditory-evoked fields of 43 children (27 LP, 16 controls) were recorded while passively listening to 100-ms white noise bursts with temporal gaps of 3, 6, 10 and 30 ms inserted after 5 or 50 ms. The P1m was evaluated by spatio-temporal source analysis. Psychophysical gap-detection thresholds were obtained for the same participants. Thirty-two percent of the LP children were not able to perform the early gap psychoacoustic task. In addition, LP children displayed a significant delay of the P1m during the early gap task. These findings provide evidence for a diminished neuronal representation of short auditory stimuli in the primary auditory cortex of LP children.