Background Isotretinoin is considered now one of the most important drugs in the treatment of different dermatological diseases. However, different bodysystems canbeaffected during the treatment due to isotretinoin induced apoptosis. Objectives To evaluate the clinical adverse effects and laboratory changes associated with isotretinoin used in the treatment of different dermatological diseases. Methods 73 patients on isotretinoin treatment fulfilled a questionnaire about side effects associated with isotretinoin. Complete blood count (CBC), fasting lipid profile, liver enzymes, and the inflammatory markers Monocytes/HDL ratio (MHR), Neutrophil/ lymphocyte (NLR), and Platelets/lymphocyte ratios (PLR) were assessed before treatment and monthly during the treatment period. Results The commonest adverse effects were related to dryness of skin and mucus membrane. 32.9% complained of myalgia and 12.3% arthralgia. Headache was reported in 13.7%, mood alteration in 11%, and insomnia in 12.3%. 24.5% of studied females reported menstrual irregularities. There were no statistically significant changes in CBC. TG, cholesterol, AST, ALT, and MHR significantly increased while HDL, NLR and PLR ratios significantly decreased after isotretinoin treatment. Conclusion: isotretinoin affects different body systems by side effects that are reversible in most instances; however, some of them are serious and need regular monitoring especially in high- risk patients.