Background: In a cesarean section, epidural analgesia with 0.125% bupivacaine and 1.5% lidocaine or 0.25% bupivacaine with 1.0% lidocaine concentrations can be used. A higher concentration of bupivacaine reaches better analgesia but with a higher rate of drug-related adverse events. Aim: The aim of the study was to assess analgesia and safety of 0.125% bupivacaine and 1.5% lidocaine or 0.25% bupivacaine with 1.0% lidocaine during cesarean. Materials and methods: Prospective cohort stratified following both bupivacaine concentrations. Results: One hundred women with full-term pregnancies were selected (fifty per cohort). At 20 and 30 min after epidural administration, there was a higher proportion of motor blockade cases from the 0.125% bupivacaine and 1.5% lidocaine cohort (p = 0.0229 and p = 0.0006, respectively). There was no significant difference among sensitive blockage. A 0.25% bupivacaine and 1.0% lidocaine concentration showed a tendency to hypotension (p < 0.001) and bradycardia (p = 0.4100). From 0.125% bupivacaine and 1.5% lidocaine cohort, 25 cases (50%) presented at least one adverse event; in contrast with 44/50 (88%) from 0.25% bupivacaine and 1.0% lidocaine cohort (p < 0.001). Conclusion: In epidural analgesia during cesarean, using 0.125% bupivacaine and 1.5% lidocaine presented similar analgesia than 0.25% bupivacaine and 1.0% lidocaine. However, a higher bupivacaine concentration is significantly related to more frequent drug-related adverse events (especially hypotension).