The aim of this study was to evaluate clinically and radiographically the outcomes of using short implants as an alternative for sinus lift in extreme atrophic maxilla. Patients and methods: partially edentulous patients of both sexes (mean age 31.5 years, range 27.0–55.3 years, seven women and five men) were selected from the out-patient clinic, Faculty of Oral and Dental Medicine, Boys, Cairo, Al-Azhar University. The patients were divided into two groups: Group (I) the patients were treated with dental short implant placement without sinus lift, (eight implants with short length 5mm). Group (II) the patients were treated with dental implant placement after sinus lift, (four implants with long length which higher than bone 2-3 mm) according to case. Patient examination past medical history, past dental history, chief complaint). Radiographic examination (by panoramic X-ray & Cone Bram C.T. Presurgery and Postsurgery 0,3,6 months). Surgical procedures for implant installation. After muco-periosteal flap was performed in the prepared surgical site, large round surgical bur (no. 6) rotating at very low-speed was introduced at the prospective implant site in the maxilla to create bony concavity which is necessary for stable direction control of Pilot drill. Then, the implant was slowly threaded into the bone using ratchet or handle instrument by a clockwise direction under external saline irrigation. Topical ointment antibiotic was applied, then fixture was covered after black retraction suture was removed, then thorough debridement and irrigation of the surgical field with sterile normal saline solution. The flap was repositioned and sutured. Methods of evaluation: all implants were tested for proper osseointegration, function and absence of mobility at three and six months after surgery. The condition of the gingival tissues around the fixture abutments was evaluated according to Loe and Sillness. Radiographic Evaluation: all subjects of the study were submitted to Cone Beam scanning before implant placement, another cone beam C.T. was taken immediately after placement, after 3 months and after 6 months forbone density measurements (densitometry analysis) and crestal bone resorption. Results: the mean value of crestal bone loss was 0.29 mm, with a maximum of 1.77 mm.  No significant differences were found in the rate of bone thickness loss between group (I) and group (II) (P=0.191). The mean value of bone loss increased in longer implants, but the difference was not significant (P=0.313). Spearman's correlation coefficient was 0.039 between the mean value of bone loss and implant length (P=0.717) and 0.242 between the patients' age and implant length (P=0.068). On conclusion; I) Short implants' is successful treatment modality to avoid invasive surgical treatments at atrophic areas of posterior maxilla, such as bone grafts and sinus lifting. II) The reconstruction of edentulous, atrophic jaws according to functional and aesthetic factors not only restores chewing function, but leads to positive psychosocial effect and thus also improves the patient quality of life.