The Turnaround time of analyses results is defined as the delay from biological prescription to the results delivery. The medical decision often depends on the results of biological tests. The purpose of this study is to analyse quantitatively the delay of the results delivery period of the biochemical tests which are urgently requested. It is a prospective and descriptive study on a period of a whole week done in Paraclinical Training and Biochemistry Research Unit of the Joseph Ravoahangy Andrianavalona University Hospital Center during the period of the on- call duty. A total of 129 files were recorded. The delay of the delivery of average results is 295 minutes with extremes of 35 and 368 minutes. The majority of requests contains 3 parameters per request. Many causes of the delay of the results are identified in this study such as the lack of staff in care services and at the laboratory, a long analysis circuit, the absence of automation of the pre and post analytic stages within our laboratory.