Making our lives more and more comfortable we pollute the environment where we live. Often toxic trace metal ions are released and spread into the surrounding, where they will be taken up into the biological chain ending very often inside us causing different diseases. When a human has been exposed to some kind of harm, it is critical to find quickly the substance causing the poisoning. It is critical to identify this polluting substance or compound and also to measure its concentration to find the best way for cure. One of the most inexpensive ways to perform chemical analyses of a large variety of heavy metal ions is to use electrochemical methods. Unfortunately voltammetric analytical methods require often sample pre-treatment. To overcome this kind of problem the ultrasound has been taken into arsenal of electrochemistry. The applied ultrasound provides continuous cleaning removing adsorbing organic compounds off the sensing electrode surface during the analysis of the analytes providing a fast sample pre-treatment free electroanalysis. This book is dedicated to the sonoelectroanalysis of cadmium, lead and zinc ions from a human blood.