Purpose: To present causes of cervical mucus problems leading to poor postcoital tests and options for treatment. Methods: Presentation of mostly original research dealing with diagnosis and treatment of cervical mucus abnormalities. Results: The simplest but least effective therapy was guaifenesin. Short-term use of ethinyl estradiol can be effective. Sometimes he ethinyl estradiol must be used for a longer time period which suppresses follicular maturation, so exogenous gonadotropin must be used to counteract suppression. Conclusions: In contrast to the conclusions of a meta-analysis by Griffith and Grimes the author believes that performing a postcoital test is a very valuable tool in investigating infertility as long as it is performed at the appropriate time as determined by serum estradiol, progesterone, luteinizing hormone and ultrasound. Clomiphene citrate therapy is the most common etiology for abnormal postcoital tests in the modern era.