To evaluate the efficacy of a thermo-sensitive punctum plug, (SmartPlug (TM)) in Primary Sjogren's Syndrome (pSS) patients with dry eyes, whose symptoms persist despite preservative-free artificial tear treatment. In this study, 22 Primary Sjogren's Syndrome (pSS), as defined by American-European Consensus Group Classification Criteria. All patients being followed up by Ege University Departments of Rheumatology and Ophthalmology. The patients had positive Schirmer test results (< 5 mm without anesthesia). SmartPlug (TM) (Medennium, Irvine, California, USA) was inserted into the inferior lacrimal canaliculi of both eyes. Visual acuity measurements, Schirmer I test measurements, lissamine green staining scores, and tear-film breakup times (BUT) were noted before plug insertion and at the 1st, 6th, and 12th months following the procedure. Minimum follow-up period was 6 months for 19 patients and 12 months for 16 patients. Significant improvements were seen in the Schirmer I test scores (before insertion: 1.98 +/- A 2.67; 1st month: 5.68 +/- A 6.69; 6th month: 5.35 +/- A 5.38; 12th month 6.43 +/- A 5.14 P = 0.006), tear-film BUT in seconds (before insertion: 4.64 +/- A 3.7; 1st month: 5.80 +/- A 2.36; 6th month: 7.53 +/- A 2.92; 12th month 7.50 +/- A 2.52, P < 0.0001), respectively. Thermodynamic punctum plug insertion only in inferior canaliculus is a simple, effective, and comfortable option for treatment of severe aqueous tear deficiency that cannot be controlled using preservative-free tears.