Purpose of Review Urolithiasis is a disease of prevalence across the world and up to a quarter of patients present with multiple stones. Most procedures carried out in this scenario are staged; however, there is a growing body of evidence to suggest bilateral simultaneous (BS) procedures are safe. We performed a systematic review to investigate and evaluate the evidence for these procedures. Recent Findings A systematic review was conducted according to Cochrane and PRISMA checklist for all English-language articles from January 1996 to January 2018 using Medline, CINAHL, Scopus, EMBASE, Cochrane library, Clinicaltrials.gov and Google Scholar. All studies (a minimum of 10 patients) with bilateral simultaneous percutaneous nephrolithotomy (BS-PCNL) or bilateral simultaneous ureteroscopy (BS-URS) and ipsilateral URS with contralateral simultaneous PCNL were included. Data was extracted for patient and stone demographics, outcomes and stone-free rate (SFR) and the level of evidence (using the GRADE assessment tool). Overall, 32 studies (1966 patients) were included in the review after the identification of 302 articles in the search. This included 16 studies (1073 patients) with BS-URS, 13 studies (750 patients) with BS-PCNL and 3 studies (143 patients) with URS and simultaneous contralateral PCNL. Of these, 8 were comparative studies and compared bilateral simultaneous procedure to either a unilateral or staged comparator. The mean operating time, SFR, the Clavien I-II and the Clavien ≥ III were 75 min, 91%, 22% and 1.4% for BS-URS; 157 min, 92%, 27% and 6.4% for BS-PCNL; 151 min, 76% and 5.6% for URS with contralateral PCNL. In comparison to staged procedures, although the SFR and complication rates were similar, there was a significantly reduced operative time and hospital stay with simultaneous procedures (p < 0.001). Summary Although evidence for bilateral simultaneous endourological procedures is limited, results from available studies show that outcomes are at least equivalent to staged procedures. Key advantages seem to be reduced operative times, cost and hospital stay which will lead to an increased uptake of these procedures in the future.