INTRODUCTION: The possibility of placing implants can sometimes be limited due to physical conditions e.g. where the horizontal space is limited by adjacent teeth and roots, or in situations with a narrow alveolar ridge. By using a narrow implant, the need for bone augmentation or orthodontic tooth movement can be avoided. OBJECTIVES: This study was designed to evaluate the use of narrow implants for replacement of lower single rooted teeth in narrow lower ridge. MATERIALS AND METHODS: Ten patients were selected from the Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, Alexandria University with missing lower single rooted tooth or teeth and narrow ridge (6mm thick or less) then implants were placed and they were evaluated by radiographic examination to evaluate the bone density around the implants after 1, 3, 6 months. RESULTS: The mean periimplant probing depth was 2.18 ± 0.55 on the 3rd month and 1.50 ± 0.52 on the 6th month, there was statistically significant decrease. As for the mean marginal bone height was 0 ± 0 immediately postoperative, 0.26 ± 0.14 on the 3rd month and 0.45 ± 0.16 on the 6th month, there was statistically significant increase. Also the results of the present study showed the mean bone density was 79.63 ± 8.55 immediately postoperative then increased on the 3rd month to be 86.35 ± 6.48 and 92.01 ± 5.49 on the 6th month, there was statistically significant increase. CONCLUSIONS: Narrow diameter implants can be used to restore missing single rooted teeth with narrow ridge.