The study was designed according to the draft of allergenic product regulation published by Spanish Regulatory Agency. The aim of the study is to evaluate the safety and tolerability of subcutaneous immunotherapy with polimerized (100/100) mixture of pollens: Olea europaea and Phleum pratense in patients with rhinoconjunctivitis with or without associated mild asthma. In addition, surrogate efficacy parameters will be evaluated: immunoglobulin level changes and skin reactivity.

Inclusion Criteria:

1. Patients must sign the Informed Consent Form.

2. Patients must be between 18 and 60 years of age.

3. Patients with seasonal allergic rhinoconjunctivitis produced by Phleum pratense and Olea europaea during at least 2 years prior to participating in the study. Although the pathology being studied is allergic rhinoconjunctivitis, patients who have concomitant mild or moderate asthma may be included.

4. Patients who have had a skin prick test result ≥ 3 mm in diameter against Phleum pratense and Olea europaea.

5. Patients who have specific IgE ≥ class 2 (CAP/PHADIA) to Phleum pratense and Olea europaea.

6. Patients will preferably be polysensitized to Phleum pratense. Polysensitized patients to otherallergenic sources may only be included in the study if their other sensitizations are produced by:

   1. Overlapping seasonal pollens which are cross-reactive with Phleum pratense and Olea europaea.
   2. Pollens whose seasons do not overlap with Phleum pratense or Olea europaea and which are not expected to produce symptoms during the study period.
   3. Other allergens which are not expected to produce symptoms during the study period.

7. Women of child-bearing potential must have a negative urine pregnancy test at the time they begin the study.

8. Furthermore, women of child-bearing potential must agree to use adequate contraceptive methods during this study if they are sexually active.

Exclusion Criteria:

1. Patients who received immunotherapy in the previous 5 years for Phleum pratense and Olea europaea or for any allergen with cross reactivity or patients that are currently receiving immunotherapy for any allergen.
2. Patients with severe asthma or forzed expiratoy volumen in 1 second FEV1< 70% even if the are pharmacologically controlled .
3. Patients with: immunological, cardiac, renal or hepatic illnesses or any other medical condition that the investigator deems relevant so as to interfere with the study.
4. Patients with a previous history of anaphylaxis
5. Patients with chronic urticaria,
6. Patients with moderate to severe atopic dermatitis
7. Patients who have participated in another clinical trial within 3 month prior to enrolment.
8. Patients under treatment with tricyclic antidepressives, phenothiazines , β- blockers, or Angiotensin Converting Enzyme Inhibitors (ACEI)
9. Female patients who are pregnant or breast-feeding
10. Patient who does not attend the visits