Hyperemesis gravidarum is the most severe form of nausea and vomiting in pregnancy with poor pregnancy outcome. Hormonal changes, psychological and immunological factors are attributed to the condition. Recently, prevalence of Helicobacter pylori among women with Hyperemesis gravidarum has been revealed. A descriptive, cross-sectional study was carried out at antenatal ward, Department of Obstetrics and Gynaecology, Mymensingh Medical College Hospital, Mymensingh among thirty-six purposively selected patients with Hyperemesis gravidarum to assess the clinic-biochemical profile. Data were collected through interview, physical examinations and laboratory investigations by using case record form. Statistical analyses were performed using SPSS version 20.0 for windows. Highest number 16(44.44%) of respondents were in age group 20 to 24 years with a mean of 23.81±4.55 years. Majority 29(80.56%) of the women had education less than 12 years, as many as 28(77.78%) women were housewives, and at least 14(38.89%) women had unplanned pregnancies. An overwhelming majority 29(80.56%) of women had their pregnancy duration between 8 to 12 weeks. At least 20(55.56%) of women were pregnant for first time, as many as 19(52.78%) women had duration of illness for 5 to 9 weeks, and all the women had remarkable weight loss. Cent per cent women were dehydrated, and appearance of 27(75.00%) women was ill-looking. Thyroid Stimulating Hormone (TSH), total leucocyte count and serum creatinine levels were normal for cent per cent women. As many as 15(41.67%) women had hypokalaemia, while 13(36.11%) had hyponatraemia and 3(8.33%) had hypochloraemia. Patient with Hyperemesis gravidarum often presents with ill-looking appearance, vomiting over 10 times a day, dehydration, remarkable loss of body weight and anaemia. Ketonuria, hyponatraemia, hypokalaemia and hypochloraemia are not associated with severity of illness.