Are cephalosporins good for utis?

Usually, not always: Cephalosporins can be good for uti's, but its also possible to have a UTI with bacteria that are resistant to cephalosporins. When in doubt its good to do a urine culture and sensitivity where the urine can be tested to determine the type of bacteria present and what, if any, antibiotics the bacteria are resistant to being treated with.

Yes: If the infecting organism is sensitive to the cephalosporin antibiotic chosen they are effective in uti's. Kidney infections may be better treated with a non betalactam antibiotic. Prostatitis is better treated with a quinalone or bactrim/ septra (sulfamethoxazole and trimethoprim) if the causative bacteria is susceptible.