This was a qualitative study to understand why pharmacists, asked to offer free chlamydia postal screening to Emergency Hormonal Contraception clients, had not offered screening to all eligible women. Twenty-six pharmacists completed exit interviews and 12 agreed to semi-structured in-depth interviews. Although pharmacists were keen to expand their services, they were reluctant to offer chlamydia screening to women who were married or in a long term relationship. To avoid offence they selected women based on age, education and ethnicity. The rationale for chlamydia screening in pharmacy-based EHC schemes is compromised if pharmacists do not offer screening comprehensively.