Background: Primary ciliary dyskinesia (PCD) diagnosis is based on studying ciliary function by high-speed video-microscopy (HSVM) and ciliary ultrastructure by transmission electron microscopy (TEM). Immunofluorescence (IF) analysis has been proposed as a routine test to improve PCD diagnosis rate. We show a preliminary HSVM and IF results of PCD candidate patients Methods: A cohort of patients was studied because of high clinical suspicion of PCD. Samples of ciliated nasal epithelium were obtained by brushing. HSVM for analysing ciliary beat frequency (CBF, normal ≥9Hz) and pattern (CBP, normal ≤20% dyskinetic ciliated cells) was performed using a high-speed camera and optical microscope. Samples from 30 patients were prepared for IF analysis and labelled with a panel of 4 ciliary-ultrastructure antibodies: DNAH5, DNALI1, GAS8, RSPH4A Results: We present HSVM and IF results of 30 patients. HSVM analyses showed 22 (73%) patients presented a reduced CBF and 28 (93%) an altered CBP (12 had disorganised ciliary beat, 10 immotile cilia and 6 stiff cilia). Regarding IF analysis, 23 (77%) were evaluable for all antibodies: 14 were normal and 9 had one or moreabsent proteins (6 DNAH5, 1 DNALI1, 1 DNAH5 and DNALI1 and 1 DNAH5, DNALI1 and GAS8). All cases with a defect in IF presented a concordant CBP. Only one case with a normal IF had also a normal HSVM. The other 13 cases had a normal IF but an altered CBP, for which further studies are being performed Conclusion: The combination of HSVM and IF could explain an important number of cases, although other analyses will be necessary to increase the accuracy and diagnosis rate of PCD