Magnetic resonance (MR) images were obtained from 171 patients with benign and malignant neoplasms in the uterus and ovary, by using a low magnetic-field machine with 0.22 T, and its usefulness is discussed. Small uterine neoplasms (a few mm of its diameter) can be detected as an abnormal intensity. Therefore, the detectability is helpful for determination of their staging. In addition, some adenomyosis can also detected as distinctive findings, although it is difficult to point out those diseases by other imaging modalities. From MR images of ovarian cystic tumor, the biochemical information of its fluid content can be obtained. However, it is difficult to get distinctive features from MR images of solid neoplasms. Even though the magnetic field is low such as 0.22 T, MR images are useful for diagnosis of gynecological neoplasms because of the high contrast image quality and the capability of providing tomograms with arbitrary planes.