Background: The treatment of metastatic renal cell cancer (RCC) has changed since the approval of the first tyrosine kinase inhibitor (TKI) in 2005. Since then, combination therapy with immunotherapy and TKI is considered standard-of-care. Despite multiple drug approvals, it remains unclear whether patients should be initiated on treatment immediately (within 30 days) as opposed to delay treatment (after 30 days), and if time to initiating treatment correlates with survival. Methods: Adults aged 20 years and older with newly diagnosed metastatic RCC between 2010 and 2019 were identified through the California Cancer Registry (n = 5,193). Time to treatment was calculated as duration between date of diagnosis and date of treatment initiation, then categorized into: No treatment, treatment within 30 days, between 31-60 days, and > 60 days. Association between treatment timing and overall and cancer-specific survival were assessed using Cox proportional hazard model and Fine and Gray sub-distribution hazard model accounting for competing risk. Both models included patient and baseline clinical characteristics. Results: 47.6% (n = 2,470) of patients received treatment with 30 days of diagnosis, while 24.3% received treatment between days 31-60 from diagnosis and 14.1% started treatment at 61 days or after from the time of diagnosis. After adjusting for all covariates, patients who received treatment at 61 days or later were less likely to experience mortality from cancer (HR 0.76, 95% 0.69-0.84, p < 0.0001) compared to those who started treatment within 30 days. Patients who started treatment between days 31-60 from diagnosis were also less likely to experience mortality from cancer (HR 0.82, 95% CI 0.76-0.89, p < 0.001). There were no statistically significant associations between cancer-specific survival and variables such as sex, race/ethnicity, or neighborhood SES. Conclusions: Patients who started treatment within 30 days of diagnosis of metastatic kidney cancer experienced worse cancer-specific survival compared to those who started treatment between days 30-60 or after day 61 from time of diagnosis. The differences in survival may be a reflection of tumor biology and high- versus low-risk disease groups. Further research is warranted to identify which patients benefit from early versus delayed treatment initiation.