Abstract : Imaging of renal calculi is crucial for selection of therapeutic options. Abdominal sonography and radiography are frequently indicated for stone detection with debatable indications. Study the superiority of KUB radiography or ultrasonography, as a single preliminary modality for detection of renal stone. I00 patients were selected (aged 47.9±13.1years, 76% were males) presented with renal colic. All are subjected to thorough history, abdominal radiograms, and ultrasonography. Those with ultrasonographic findings of urinary stone were enrolled, and classified according to stone size into groups of (<5.0mm), (5.0-10.0mm), and(>10.0mm). Mean patients age was 47.9±13.1years, with male predominance. Around 2/3rd of the stones were radiopaque. 43% of the stones were detected in the middle kidney pole, 31% in the ureter at different levels, 27% in the lower pole, and 16% of the stones had mixed locations. 3/4th of the cases had calcium oxalate type of stones. More than one stone revealed variable sides, locations, and types. Ultrasonography has a superior sensitivity over the KUB radiography in detecting urate and amorphous stones, besides some of the calcium, oxalate and phosphate stones. The small-sized and some of the moderate-sized stones were undetectable by the radiography, while all stone sizes can be detected by the ultrasounds. Compared with plain radiography, ultrasonography is an ultimate preliminary imaging modality for kidney stones. Adding innovative approaches can further expand the precision of stone analysis. KUB radiography in detecting small nephrolithiasis is of restricted value.