This chapter provides an overview of urinary tract infections, acute glomerulonephritis, nephrotic syndrome and hematuria. Urinary tract infection in children is based on the presence of a positive urine culture in a symptomatic child. The child has to be symptomatic, either in the form of urinary symptoms or have fever without an identifiable source. The common test used for diagnosing UTI is not included in the pure definition of UTI. Pyuria is only an indicator of inflammation and not always the sign of UTI in children. Once UTI is suspected, urine tests are required to diagnose or rule out UTI. The two tests used commonly are a routine examination of urine with microscopy and urine culture. Suprapubic aspiration of urine (using a syringe and needle to aspirate urine directly from the bladder) is possible in young children as the bladder is an abdominal organ till 5 years of age. Microscopy of the urine may reveal the presence of leukocytes. It is extremely important to realize that every \"positive\" urine test is not a UTI. A single antibiotic is adequate to clear a UTI. The term glomerulonephritis suggests inflammation in the glomeruli which leads to hematuria, oliguria, hypertension and azotemia. A combination of three factors seen together usually would signify acute glomerulonephritis: hematuria (gross or microscopic), hypertension and azotemia. The common presentation of AGN, especially PIAGN is the grossly discolored urine. The initial test would be to determine whether the discolored urine is due to blood in the urine. Gross hematuria with urinalysis with many red blood cells per high power field (RBCs/hpf) is easy to diagnose. Nephrotic syndrome is a constellation of four features: heavy proteinuria, low serum albumin, edema, hyperlipidemia. The cornerstone of diagnosis of nephrotic syndrome is heavy proteinuria. Without proteinuria, nephrotic syndrome cannot be the diagnosis. Once diagnosed as nephrotic syndrome, the age of the child will determine the treatment offered. Discolored urine is one of the symptoms that causes distress and anxiety in parents of a child. It is not an uncommon symptom in children. When a child presents with discolored urine (urine looking red, pink, brown, dark, smoky or black), one needs to look for hematuria.