Background : Early loss of a second deciduous molar before the eruption of first permanent molar can lead to marked space deficiency in the dental arch. The distal shoe space maintainer is indicated in such situation to prevent space loss. Incorrect positioning of the distal shoe is a common error. Information is lacking regarding its effectiveness in maintaining space, the gingival response and patient`s tolerance to it. Methods: The subjects consisted of 15 children with an age range from 5-6 years. All patients had lower second primary molars indicated for extractions and unerupted lower first permanent molars. The position of the distal shoe was identified and recorded on a periapical radiograph taken using a special radiographic stent. The appliance was then fabricated on the study model and fitted intraorally immediately after the extraction of the second primary molar. The gingival response using bleeding on probing index(BOP) and patient`s tolerance were assessed after 2 months postoperatively. After the eruption of the first permanent molar an impression was taken to assess space changes. Results: The mean space loss was 0.27 mm (p-value >0.1). The BOP was negative (P < 0.05 ). The patient tolerated the DSSM well (P < 0.00000) . Conclusion: Distal shoe space maintainer is an effective and safe appliance for maintenance the space of extracted lower second primary molar before eruption of first permanent molars