Field experiment was carried out at NIHORT, Ibadan in 1998 to determine the effect of planting date on eggplant and maize on their performance in mixtures. Eggplant and maize were planted on 10th July, 1998 and 24th July, 1998. Seven treatments were investigated in which eggplant and maize were planted together or two weeks later, viz: maize + eggplant (same day), maize + eggplant (eggplant introduced 2 weeks after planting maize), maize + eggplant (maize introduced 2 weeks after planting eggplant), their respective sole crops were planted for comparison. The experiment was laid out in a randomized complete block design replicated three times. The result showed that planting maize on 24th July, 1998 increased maize yield while 10th July planting was favourable to eggplant. Intercropping reduced the yield of eggplant while maize yield was enhanced. The LER, 2.0, 2.26 and 1.37 also the ATER, 2.29, 2.5 and 1.5 showed that maize+eggplant Intercropping is highly productive and compatible. The CAI showed that eggplant + maize (maize planted two weeks after eggplant) was the least profitable while maize + eggplant (eggplant introduced 2 weeks after maize) intercrop had the highest economic returns.