An organism’s approach and avoidance behavior is facilitated by correct discrimination of odor valence; a task considered to be one of the main objectives of the olfactory system. Odor valence processing has in previous work been shown to take place as early as in the olfactory bulb. However, how this information in humans is transmitted further into the olfactory cortex is not known. Here, we introduce two studies where participants were presented with odors and rated their perceived valence after each trial. Neural responses in the olfactory bulb and olfactory cortex were reconstructed using the collected EEG. Functional connectivity between these two areas was determined by the coherence spectrum and was related to perceived valence through decoding accuracy of support vector machine learning. Moreover, effective connectivity was determined by frequency resolved granger causality. In both studies we demonstrate direction-dependent communication where the olfactory bulb communicates odor valence to the olfactory cortex in the gamma band while the olfactory cortex later communicates back in the beta band. The early gamma activity is predicted by high unpleasantness ratings and the later beta activity is predicted by low unpleasantness ratings in both studies. These results demonstrate that the olfactory bulb and the olfactory cortex primarily communicate degrees of odor unpleasantness across multiple frequencies in a direction-dependent manner.