A community pharmacist has expert knowledge of medications and can advise members of the public in this matter and will also give advice on over-the-counter remedies that can be purchased for minor ailments or non-serious illnesses such as a cold. They may also recommend a visit to a doctor if they think it is necessary. The pharmacy is often the first point of call for someone suffering from a minor illness or in the initial stages of an illness and relevant advice is given.

In hospital pharmacies, the job involves more specific drug measurements and preparations - for example perhaps confirming prescribed calculations of doses dependent on the patient's weight, and making sure that the correct dose is given. Hospital pharmacies deal with stronger and more dangerous drugs more often than community pharmacies do and provide a vital service within the hospital. Generally, all pharmacists have expert knowledge about medicines and can apply this in different ways depending on their chosen speciality or area of work.

In some countries now, especially in Europe, community pharmacists have been given prescribing power. This means that there are certain medications that can be prescribed by the pharmacist after a brief consultation with a patient. Additional requirements are often required of the pharmacist in order to be allowed to prescribe certain medications.