Abstract: Methods and devices are provided for guiding and inserting a tool into an object, such as tissue. In an exemplary embodiment, a guidance and insertion device is provided that can be remotely controlled to adjust an insertion trajectory of a tool, and to advance the tool into tissue to a desired penetration depth. The tool can be, for example, a biopsy device, a brachytherapy device, or a lumpectomy device. The device can be configured for use with an imaging apparatus, such as computed tomography (CT) images, to allow the device and tool to be operated while viewing the device positioned in relation to a target surgical site. The device can also be configured to be positioned directly on a patient, so as to passively compensate for respiratory chest motion, and it can include features to passively compensate for needle oscillation. In other exemplary embodiments, the device can be entirely disposable.