Abstract. Full text available at https://www.ajol.info/index.php/thrb/article/view/63671/56049The importance of an ultrasound in diagnosis of bladder tumours has been investigated by different authors. Some have questioned its effectiveness while others have considered the technique to be an important tool in the initial evaluation of bladder tumours. This study was carried out to establish the effectiveness of the ultrasound in diagnosis of bladder tumours at the Muhimbili National Hospital in Dar es Salaam, Tanzania. Clinical indications and ultrasound findings were recorded. Cystoscopy was done and findings recorded on a preformed questionnaire. The ultrasound findings were compared to cystoscopy findings and the sensitivity, negativity, positive predictive value and negative predictive value determined. A total of 110 patients were recruited in this study and the male to female ratio was 2:1. The commonest (37%) age group was 41-60 years. The most common clinical indication overall was haematuria in 37% of all cases. In males, bladder outlet obstruction due to stricture was the commonest indication (31%). Out of 110 patients scheduled for cystoscopy, 71 had ultrasound done preoperatively. In these patients 70% had some form of abnormal ultrasound findings. The sensitivity, specificity, positive predictive value, and the negative predictive value (NPV) of ultrasound in detection of bladder tumour were 83%, 93%, 89% and 89%, respectively. In conclusion, ultrasound is an effective method for evaluating patients presenting with haematuria or suspected to have bladder tumours. It is cheap, available, affordable and non-invasive; has a high sensitivity, and therefore it can also be useful in the follow-up of patient with bladder cancer.