Temporary electrodes implanted under general anaesthesia, or via an oral or percutaneous endoscopic gastrostomy route have been used for testing of gastric electrical stimulation (GES). We have developed a principle for percutaneous electrode implantation. Leads were constructed so that the tip could be anchored to the gastric submucosa under gastroscopic control. Acute experiments were performed in anaesthetized pigs. Three patients referred for nausea and/or vomiting and non-established indications for GES (chronic intestinal pseudo-obstruction, functional dyspepsia without gastroparesis) were evaluated. Electrode function was tested by recording and stimulation techniques. In the pigs, a slow-wave (SW) rhythm (3 min−1) was recorded with decrease in frequency at the end of the experiments. In the patients, implantation time from start of gastroscopy to end of electrode placement was 12–20 min. Electrode distance varied from 12 to 45 mm. Gastric electromyography showed a regular SW rhythm of about 3 min−1. Antral pressure waves had intervals being multiples of the SW-to-SW time. With temporary GES for 7–9 days, weekly frequency of the referral symptoms decreased >80% in two patients and 33% in one patient. Temporary percutaneous gastric leads can easily be implanted and may be used for testing of GES and study of gastric electrophysiology.