BACKGROUND Tandem spinal stenosis (TSS) has a complex clinical presentation, and there is no consensus on the optimal surgical strategy. This study retrospectively compared the efficacy of different staged operations and simultaneous decompression for patients with TSS. METHODS We reviewed data from 132 patients with TSS who received surgical procedures from January 2011 to June 2018. Patients were classified into three groups according to the most symptomatic area of compression (group C: first-stage surgery for cervical compression; group L: first-stage surgery for lumbar compression; group CL: simultaneous surgery for both). Medical records were reviewed for age, gender, comorbidities, operation time, combined estimated blood loss, and time of hospitalization. The JOA-C, JOA-L, NDI, and ODI scores, and complications were also examined. RESULTS Postoperative outcomes were followed for 32.1 ± 5.4 months. There were significant differences in the re-operation rate and the interval time between the two types of staged operations (p = 0.005 and p = 0.001, respectively). There were no significant differences in gender (p = 0.639), operation time (p = 0.138), combined estimated blood loss (p = 0.116), or complications (p = 0.652) among the three groups, while the simultaneous group was significantly younger (p = 0.027), with fewer comorbidities (p < 0.001) and a shorter hospitalization time (p < 0.001). At the final follow-up, the JOA-C and JOA-L scores were increased, while the NDI and ODI scores were decreased, compared with the preoperative scores. CONCLUSIONS TSS can be effectively managed by either simultaneous or staged decompressions. First-stage surgery for cervical stenosis significantly lowers the requirement for second-stage lumbar surgery. One-stage simultaneous decompression is safe and effective with the advantage of reduce hospitalization time, without an increase in operative time or bleeding. However, the surgical indications should be strictly controlled and is recommended for younger patients with fewer comorbidities.