Background: Nutritional anaemia is one of Nigeria’s major public health problems. One of the major causes of anaemia is poor diet arising from poor socioeconomic conditions and corruption. Objective: The objective of this study is to assess the effect of type of diet on weight and some haematologic parameters of pregnant women. Methods: A random sampling method was used to enlist the pregnant women prospectively and consecutively. A semi-structured questionnaire was used to solicit information on diet, social status and anthropometric details. The hospital folders of the respondents were reviewed and laboratory tests carried out by standard methods. Results: The investigations showed that majority of the pregnant women (56.89%) were of lower social class, poorly-educated, maintained on considerable carbohydrate and protein diet, and were in the weight bracket of 50-75 kg. 168 (95.5%) of the women were not anaemic, with Packed Cell Volume (PCV) of 0.34 ± 0.6, Haemoglobin concentration (Hb) of 11.46 ± 1.2 and Red Blood Cell (RBC) count of 3.82 ± 0.6. the anaemic women were 8 (4.5%) and had PCV of 0.28 ± 0.3, Hb of 9.33 ± 1.1, and RBC count of 3.13 ± 0.4. The differences in the haematological results between the anaemic and non-anaemic pregnant women were statistically significant, p<0.05, except for the red cell count. Conclusion: In conclusion, micronutrient supplementation and absence of under nutrition ensured the good pattern of weight gain and haematological results in most of the women. The anaemic are recommended to be investigated for other possible causal factors of anaemia.