Malignant melanoma primarily metastases to the closest lymph node. Therefore the Sentinel node biopsy (SNB) has become an essential element in the tumour node metastasis stating of cutaneous melanoma. The five year prognosis decreases dramatically if lymph node metastases are discovered compared to patients with disease free sentinel nodes: from 90% to 50-60% respectively. Therefore it is important to develop an experimental mouse model of a lymph node metastatic malignant melanoma that could serve as an instrument in the search for better treatments methods. Mouse melanoma cells were injected subcutaneously into the back of a four weeks old male BALB/c mouse. The mice were PET/CT imaged on day 5 and on day 11 after the inoculation of cancer cells. [18F]FDG PET/CT allowed visualisation and semi-quantification of metabolic activity of both the primary tumour and lymph node metastases (LN). Especially the growth of ipsilateral LN was well demonstrated, also by CT based volume. Dedicated small animal PET/CT provides a non-invasive method to study lymph node metastatic melanoma in mice. This technology can be used to test a variety of potent molecules with anti-melanoma effect.