Most physiological and behavioral functions exhibit daily rhythms synchronized with the light-dark (LD) cycle. Shift and night work desynchronizes biological rhythms, promoting cancer development. Previously, we reported in a non-metastatic murine melanoma model that chronic jet-lag (CJL, 6-hour advance of the LD cycle every 2 days) increases tumor growth rate and disrupts rhythms in immune parameters. Here, we evaluated a metastatic murine melanoma, which induces lung metastasis, in two circadian desynchronization models: CJL and Per2brdm1 mutant mice. We observed an increased metastatic development in both desynchronized mice. Regarding immune system, we found daily patterns in lung macrophage levels under LD: M1 (anti-tumoral) cells peak at the late night, while M2 (pro-tumoral) peak at the early night. These patterns were disrupted in desynchronized mice. On another hand, the deregulation of clock-related parameters has been observed in cancer patients, therefore we evaluated if metastasis development alters body rhythms. We observed a disruption in temperature rhythms, and a decrease in the strengths of locomotor activity. These findings show a bidirectional interaction between the circadian system and metastatic process: circadian desynchronization promotes metastatic development, maybe partly through immune system modulation, while the circadian system itself gets worse during tumor progression which could initiate a vicious cycle and facilitate tumor growth.