Transcranial ultrasonic stimulation (TUS) promises non-invasive and highly precise neuromodulation of small, deeply located brain regions like the basal forebrain (BF) – a cholinergic hub that is affected in neurodegenerative diseases like Alzheimer’s. Here, we aimed to combine TUS of the BF with simultaneous electroencephalography (TUS-EEG), expecting widespread desynchronization of cortical neuronal activity due to TUS-induced increases in cholinergic BF signalling.TUS transducer placement and targeting were individually planned and monitored using MRI scans as well as acoustic simulations and neuronavigation, respectively. During the experiment, two resting-state EEG (rsEEG) runs were interleaved by a simultaneous TUS-EEG run. This allowed investigation of both acute (“online”) TUS effects (as changes in the (alpha) frequency content of the post- vs. pre-TUS rsEEG data) and prolonged (“offline”) effects of TUS (using a time-frequency analysis (TFA) of the TUS-EEG data).For offline TUS effects, we found a widespread reduction in alpha power that was most pronounced over posterior occipital brain areas. In contrast, online TUS effects showed dynamic increases in alpha power closely following the onset of the stimulation.In conclusion, while our TUS-EEG setup provided EEG data of sufficient quality to test the hypotheses of interest, it needs to be further refined to allow for both more flexibility and stability in transducer placement. In addition, influences that may confound the observed EEG results (e.g., auditory effects) warrant more rigorous control in future extensions of the setup (e.g., through auditory masking or ramping of the ultrasonic pulses).