In recent years, phytoplasma diseases have increased and become serious in Egypt. Samples of carrot plants exhibiting symptoms of phytoplasma diseases were collected from seven different cultivated areas in El Qalyubia governorate during the growing season 2021 and 2022, to detect phytoplasma infection and their transability. Several detection methods include light microscopy, Dienes' stain, transmission electron microscopy (TEM), and Nested-PCR. Dodder (Cuscuta campestris), leafhopper (Hebata decipiens), seeds, and mechanical transmission were used to study the transability of phytoplasma. The obtained results showed pleomorphic bodies in treated phloem tissues with Dienes' stain as irregular patches of intensely dark blue stained cells. However, a light microscope observed significant changes in infected tissues. These results were confirmed using transmission electron microscopy (TEM) that observed phytoplasma units in the phloem tissue and deterioration in the ultrastructure of infected plants including malformed cells, thickness, and abnormal shape of the cell wall. But, due to inconsistent distribution within the plant, low titer, and fluctuation often hamper accurate phytoplasma detection. Therefore, a PCR-based assay was used to detect phytoplasma infection using the universal primer pairs P1/P7 and R16F2n/R16R2 that produce a clear band at 1200 bp. For transmission of phytoplasma in carrot, dodder, and leafhoppers gave positive results and mechanical transmission gave negative results. Our results will provide a better understanding of the effects of phytoplasma infection in carrots, helping us to develop effective strategies for overcoming such diseases.