Purpose of Investigation: To evaluate technique, advantages, and limits of saline infusion sonography (SIS) in assessment of endometrial, subendometrial, and myometrial pathologies. Materials and Methods: A detailed literature research on MEDLINE, Cochrane library, EMBASE, NLH, ClinicalTrials.gov, and Google Scholar databases was done up to December 2017 restricted to English articles regarding SIS, technique, advantages, and limits. The keywords used for this review were: sonography, ultrasonography, hydrosonography, hysterosonography, saline infusion sonography, and sonohysterosalpingography (sono-HSG) with foam instillation (HyFoSy) versus saline solution (HyCoSy) in the evaluation of tubal patency. Original articles, reviews, and meta-analyses were included. Results: SIS has acquired an important role in the diagnostic work-up of abnormal uterine bleeding (AUB). SIS can be considered as an alternative diagnostic modality to hysteroscopy in detecting endometrial polyps and uterine submucosal leiomyomas. SIS is performed before the beginning of the assisted conception to evaluate the uterine cavity and exclude intracavitary pathologies, such as fibroids and endometrial polyps that could hinder the assisted fertilization procedure. SIS has a similar sensitivity and specificity for tubal patency as hysterosalpingography (HSG), without the inconvenience and potential hazards of HSG, such as possible iodine-based sensitivity to the radiopaque dye and exposure to radiations. Two-dimensional (2D) SIS is already very accurate, therefore both 2D SIS and threedimensional (3D) SIS should be considered alternatives to diagnostic hysteroscopy when intracavitary pathology is suspected in subfertile women and in those with AUB. Conclusions: SIS is a technique indicated in premenopausal and postmenopausal women with abnormal vaginal bleeding and is also a valid procedure for initial outpatient screening in infertility.