Empirical antimicrobial treatment for acute cystitis in women requires continuing reassessment as the antimicrobial susceptibility of community isolates of Escherichia coli evolves. Current recommendations for 3 days trimethoprim or trimethoprim/sulphamethoxazole are compromised by increasing resistance of community E. coli to these agents. Fluoroquinolones are an alternate 3-day therapy, but increasing resistance is being reported from some countries, and widespread community use may promote resistance, limiting effectiveness of these agents for more serious infections. Alternate regimens supported by recent clinical trials suggest pivmecillinam given twice daily for 7 days is as effective as 3 days of quinolone therapy, while microbiological cure is 80% with 3 days therapy twice daily, and 90% with 3 days therapy thrice daily. Nitrofurantoin given for 7 days has a cure rate of 80-85%. Fosfomycin trometamol as a single dose has cure rates of 75-85%. All these agents are effective, but a compromise in efficacy or duration of therapy compared with current 3-day regimens may have to be considered.