Integrated electronic prescribing systems (IEPSs) are expected to improve efficiency and safety in the management of pharmaceuticals throughout the healthcare sector. In Sweden (population 9 million), more than 25 million e-prescriptions each year are processed in the National IEPS. We set out to examine the introduction of an IEPS into pharmacists’ practice with regard to impact on work efficiency and pharmacological safety. A questionnaire was distributed to all pharmacists (n = 74) in a Swedish municipality (population 145,000), where an IEPS had recently been introduced. The response rate was 70%. The IEPS was in general perceived to have expedited the processing of prescriptions and reduced the risk for prescription errors as well as the handing over of erroneous medications to patients. We found that there was a positive correlation between usefulness of the IEPS system for work efficacy and pharmacological safety, respectively (r =0 .524, p < .001) and a negative correlation between the usefulness of the IEPS for work efficacy and perception of barriers to technology use (r = −0.010, p > 0.05). We also found that there was a negative correlation between IEPS usefulness for pharmacological safety and that barriers to IEPS technology use were experienced (r = 0.031, p > 0.05). The results indicate that reduction of system unavailability due to technical issues will increase the perceived usefulness of IEPSs for pharmacists with regard to both work efficacy and pharmacological safety. We conclude that the introduction of an IEPS was well received by pharmacists; however, barriers to full acceptance remained, in particular, system unavailability due to technical problems.