Purpose: To compare the two non-surgical periodontal treatment methods with regard to socioeconomic aspects, treatment results and complications. Methods and Results: Twenty-five patients were randomly divided into two groups for non-surgical treatment consisting of scaling and root planing. One group had intensive treatment (InT) performed within 24 h and the other group received conventional treatment (CoT) with one treatment session a week for 4 weeks. All the patients rinsed their mouth with chlorhexidine 0.2% after each treatment session for 5 weeks. The investigation before and after the treatment was performed by the same clinician blinded to the treatment modalities, and all the treatments were performed by the same dental hygienist. Treatment had significantly reduced the number of pockets in both the treatment groups, but there was no difference between the two treatment modalities regarding pocket reduction or reported discomfort/pain graded on the visual analogue scale. Only one patient receiving the InT was not satisfied. However, in the CoT group six patients answered that they would have preferred the InT, whereas the remaining patients answered that it did not matter whether they received InT or CoT. The patients in the CoT group consumed more analgesics after the treatment. The mean total travelling time for the InT group was 113 min compared with 357 min for the CoT group. Conclusions: Most patients preferred the InT if they were to undergo the treatment again. Furthermore, InT resulted in a substantial socioeconomic gain with no difference in the treatment result and the complication rate compared with CoT. Keywords: full-mouth periodontal therapy, periodontal treatment, scaling and root planing