The diagnosis of decompression sickness (DCS) is mostly based on clinical suspicion, and there is currently no available modality to fully confirm the diagnosis. However, the use of echocardiography in suspected DCS cases has become more common. In this case, transthoracic echocardiography (TTE) was used to detect microbubbles in the right cardiac chambers and monitor the patient after hyperbaric oxygen therapy (HBOT), suggesting the possible applicability of TTE in diagnosing and monitoring DCS patients. This report describes a 54-year-old Fisherman who was referred to the emergency department with dyspnea and mild confusion after a rapid ascent of a saturation dive at 50 m sea depth. After the initial evaluation, he was assessed using TTE to exclude the presence of structural heart disease, where it surprisingly showed spontaneous echo contrast inside the right cardiac chambers similar to agitated saline echo testing. The patient was then admitted for HBOT and follow-up; rapid improvement was noticed after the first HBOT session and the TTE findings were fully resolved. TTE could be considered in the initial workup when DCS is suspected, and it might have a role in monitoring DCS patients if echocardiographic findings of bubble formation were documented in the pre-hyperbaric therapy settings.