Background: Limitations in the technical capabilities of the fiberoptic echoendoscope often necessitate concurrent diagnostic endoscopy at the time of an endosonographic (EUS) examination. Our aim was to determine whether a new video echoendoscope would allow the performance of EUS without diagnostic endoscopy. Methods: EUS examinations on all patients at two centers were initiated with a fiberoptic echoendoscope (period of 5 weeks) or a video echoendoscope (period of 6 weeks). Note was made of need for concurrent diagnostic endoscopy. The endosonographer also rated the mechanical, optical, and sonographic performance of the video instrument using a 9-point comparative scale (1 = much worse, 5 = equal to, and 9 = much better than fiberoptic echoendoscope). Results: A total of 103 patients including 40 and 28 with mural lesions and 22 and 15 with retroperitoneal lesions were examined with the fiberoptic and video echoendoscopes, respectively. Mean values for parameters rating the video echoendoscope's mechanical performance ranged between 5.0 and 5.9, optical performance ranged between 6.6 and 7.5, and sonographic performance ranged between 4.6 and 4.9. Concurrent diagnostic endoscopy was required less frequently when patients with mural lesions (18% vs. 70%, p < 0.005) or patients with retroperitoneal lesions (0% vs. 14%, p = no significance) were examined with the video echoendoscope compared with the fiberoptic echoendoscope. Conclusions: Moderately improved optics and slightly better mechanical characteristics of the new video echoendoscope allow the performance of EUS without concurrent diagnostic endoscopy in the majority of patients. (Gastrointest Endosc 1999;49:695-9.)