Quality of medical care should be the highest priority with every department in every hospital, and this is especially true for the emergency department [ED], Guidelines should be seen as only one strategy that can help improve the quality of care that patients receive. This study conducted to determine the effect of development and dissemination of practice guidelines on the quality of care provided to patients presenting with three selected complaints, namely: dyspnea, abdominal pain, and chest pain at ED of Abou Kir General Hospital. The study was carried out at ED of Abou Kir General Hospital in Alexandria, a 180-bed hospital affiliated to Ministry of Health and Population. The study was a quasiexpermental, before and after approach and consisted of three phases. Comparison of process of care before and after intervention was done. The intervention was educational. Observation check lists were used for assessment of adherence to certain elements of process of care based on the developed and validated clinical practice guidelines of dyspnea, abdominal pain, and chest pain during pre- and post-intervention phase. The guidelines were presented to emergency physicians during the three-week interval between the pre- and post-intervention phases and after conduction of workshop. All physicians [18 physicians] working in ED were included in the study. All [258] patients presenting at ED with the three selected complaints: dyspnea, abdominal pain, or chest pain, were included in the study. The study concluded that development and implementation of guidelines for patients presenting at ED with acute dyspnea, acute chest pain, and acute abdominal pain improved compliance of physicians with these guidelines and improve the process of care. The lowest compliance weighted mean score percent concerning the three selected conditions was for history items during both pre-intervention phase [ranging between 4.7% and 28.4%] and post-intervention phase [ranging between 19.7% and 48.9%]. With respect to physical examination area, there was statistically significant improvement in weighted mean score percent for the three selected conditions with highest improvement for abdominal pain [from 30.7% to 50.4%]. As regards management area, there was no statistically significant improvement in weighted mean score percent for the three selected conditions. With highest improvement for dyspnea [from 88.7% to 99.0%]. Based on this study it is recommended to target improvement of the overall knowledge and skills of Emergency Department physicians, as most physicians are not emergency medicine specialists. More time must be allocated to training in the accident and emergency departments than at present; this should be supported by making available more detailed and comprehensive clinical guidelines. Also greater use of complementary educational methods such as practical skill training, case presentation, and clinical audit are very important.