New system of registration of primary morbidity was developed for the purpose of elimination of systemic error factors and decrease of human element input. The following principles are included: simplification of registration rules; more exact registration of acute conditions; unified rules of registration for out-patient and in-patient medical institutions; unified form of information fields in medical documentation for morbidity registration in out-patient and in-patient medical institutions; succession in basic parameters, indicators and terms of medical statistics in currently in force and modernized systems. New system includes following information fields: "stage of diagnostics", "urgency of condition"; "ICD-10 code", "diagnosis", "life identification", "calendar year identification". All fields, except field "diagnosis", are formalized and for them (except field "ICD-10 code") corresponding codings are developed. Rules for filling information fields, algorithms of validity control of primary information and receiving such indicators as first time identified morbidity", "chronic morbidity", "emergency (acute) morbidity", "chronic sickliness/morbidity identified for the first time in previous years", "chronic sickliness" are developed. This system is implemented experimentally in medical institutions of primary and secondary levels of health care system in Yakka-Saraysk district of City of Tashkent.