Third molar extraction is one of the most common procedures in oral surgery. However, it is still unclear whether extracting the two lower third molars in two separate sessions or one appointment is preferable. This randomised controlled trial, including 100 patients, aimed to compare unilateral with bilateral lower third molar extraction under local anaesthesia. We recorded downtime, pain level, dysphagia, hypoesthesia, additional clinic contacts and group preference. In the bilateral study group, two patients preferred not to proceed after the first side (3.8%, n = 2/53). Thirteen patients (27.7%, n = 13/47) did not show up for the second operation in the control group. The mean sick leave duration was significantly lower in the bilateral study group (3.47 days) than in the unilateral control group (6.03 days, t-test: p-value<0.05). Patients with bilateral extraction did not report higher pain levels or more difficulties with swallowing than the unilateral control group. There was no significant difference between the groups regarding hypoesthesia and additional clinic contacts. Our randomised controlled trial could demonstrate that bilateral lower third molar extraction under local anaesthesia is safe and well accepted by patients. Two separate appointments were associated with higher pain levels, experiencing the pain twice, and the double number of days off work or school. Furthermore, bilateral procedures in a single appointment save resources, as only one surgical set and one sterilisation process are needed. In conclusion, based on our experience, we recommend offering bilateral extraction of the lower third molars in a single visit to reduce overall patients’ physical and psychological discomfort. Additionally, from a socio-economic perspective, workload and costs are lower for the health system - one single surgical set and sterilisation - and the society - half downtime.